I'm trying to install Mysql 5.6 on Debian 7 Wheezy..

After installing the mysql database/folder /var/lib/mysql/mysql is empty

# groupadd mysql
# useradd -r -g mysql mysql
# apt-get install libaio1
# wget http://cdn.mysql.com/Downloads/MySQL-5.6/mysql-5.6.12-debian6.0-x86_64.deb
# dpkg -i mysql-5.6.12-debian6.0-x86_64.deb
# cd /usr/local
# ln -s /opt/mysql/server-5.6 mysql
# cd mysql
# scripts/mysql_install_db --user=mysql --datadir=/var/lib/mysql
# rm /opt/mysql/server-5.6/my.cnf
# rm /etc/mysql/my.cnf
# ln -s /var/ini/my.cnf /opt/mysql/server-5.6/my.cnf
# chown -R root .
# chown -R mysql /var/lib/mysql
# cp support-files/mysql.server /etc/init.d/mysql
# alias mysql=/opt/mysql/server-5.6/bin/mysql
# alias mysqladmin=/opt/mysql/server-5.6/bin/mysqladmin

# service mysql start
# update-rc.d mysql defaults

my.cnf

#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr/local/mysql
datadir     = /var/lib/mysql
tmpdir      = /tmp
lc-messages-dir = /opt/mysql/server-5.6/share/english
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address        = 127.0.0.1
#
# * Fine Tuning
#
key_buffer      = 16M
max_allowed_packet  = 16M
thread_stack        = 192K
thread_cache_size       = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover         = BACKUP
#max_connections        = 100
#table_cache            = 64
#thread_concurrency     = 10
#
# * Query Cache Configuration
#
query_cache_limit   = 1M
query_cache_size        = 16M
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
#
# Here you can see queries with especially long duration
#log_slow_queries   = /var/log/mysql/mysql-slow.log
#long_query_time = 2
#log-queries-not-using-indexes
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id      = 1
#log_bin            = /var/log/mysql/mysql-bin.log
expire_logs_days    = 10
max_binlog_size         = 100M
#binlog_do_db       = include_database_name
#binlog_ignore_db   = include_database_name
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem



[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer      = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/

error

130619 14:28:13 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
2013-06-19 14:28:14 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2013-06-19 14:28:14 6582 [Warning] Using pre 5.5 semantics to load error messages from /opt/mysql/server-5.6/share/english/.
2013-06-19 14:28:14 6582 [Warning] If this is not intended, refer to the documentation for valid usage of --lc-messages-dir and --language parameters.
2013-06-19 14:28:14 6582 [Note] Plugin 'FEDERATED' is disabled.
/usr/local/mysql/bin/mysqld: Table 'mysql.plugin' doesn't exist
2013-06-19 14:28:14 6582 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
2013-06-19 14:28:14 6582 [Note] InnoDB: The InnoDB memory heap is disabled
2013-06-19 14:28:14 6582 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2013-06-19 14:28:14 6582 [Note] InnoDB: Compressed tables use zlib 1.2.3
2013-06-19 14:28:14 6582 [Note] InnoDB: Using Linux native AIO
2013-06-19 14:28:14 6582 [Note] InnoDB: Not using CPU crc32 instructions
2013-06-19 14:28:14 6582 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2013-06-19 14:28:14 6582 [Note] InnoDB: Completed initialization of buffer pool
2013-06-19 14:28:14 6582 [Note] InnoDB: Highest supported file format is Barracuda.
2013-06-19 14:28:14 6582 [Note] InnoDB: 128 rollback segment(s) are active.
2013-06-19 14:28:14 6582 [Note] InnoDB: Waiting for purge to start
2013-06-19 14:28:14 6582 [Note] InnoDB: 5.6.12 started; log sequence number 1600637
2013-06-19 14:28:14 6582 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306
2013-06-19 14:28:14 6582 [Note]   - '127.0.0.1' resolves to '127.0.0.1';
2013-06-19 14:28:14 6582 [Note] Server socket created on IP: '127.0.0.1'.
2013-06-19 14:28:14 6582 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist
130619 14:28:14 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

I am using Ubuntu (Debian based) and followed very similar steps successfully. However I downloaded the debian package, not the binary:
http://downloads.mysql.com/archives/mysql-5.6/mysql-5.6.11-debian6.0-x86_64.deb

then I ran:

sudo apt-get install libaio1
sudo groupadd mysql
sudo useradd -r -g mysql mysql
wget -O mysql-5.6.11-debian6.0-x86_64.deb \
  http://downloads.mysql.com/archives/mysql-5.6/mysql-5.6.11-debian6.0-x86_64.deb
sudo dpkg -i mysql-5.6.11-debian6.0-x86_64.deb
cd /usr/local
sudo ln -s /opt/mysql/server-5.6 mysql
cd mysql
sudo scripts/mysql_install_db --user=mysql
sudo chown -R root .
sudo chown -R mysql data
sudo cp support-files/mysql.server /etc/init.d/mysql
sudo service mysql start
sudo ./bin/mysql_secure_installation

The last step is optional.

EDIT

I just downloaded the .tar.gz you used and this is the sources. So basically you need to install CMAKE and build MySQL yourself. I did that 2 weeks ago and it's not that difficult (if you have already built stuff on linux before :) ) but I doubt you need to go through this burden. You just need to find out what errors are reported with the .deb installation and share it here so we can help.

UPDATE

For the issue starting MySQL, in the /etc/init.d/mysql file (copied from /opt/mysql/server-5.6/support-files/mysql.server in the steps above) change around lines 48-49 the empty

basedir=
datadir=

to

basedir=/usr/local/mysql
datadir=/usr/local/mysql/data

(or whatever path needed)

Note you might need to add in the [client] and [mysqld] sections of your /etc/my.cnf (this debian package expects this file in /etc OR /opt/mysql/server-5.6 not /etc/mysql)

socket = /var/run/mysqld/mysqld.sock

Or you might have issues connecting from PHP or other programming language.

I suggest using the official apt repos launched yesterday: http://mysqlrelease.com/2014/05/theyre-here-official-mysql-repos-for-debian-and-ubuntu/

Debian 7 is included as a supported platform. The package format is also much more debian-like, than the .debs

Use the dotdeb.org repository which releases high-quality packages in a timely manner.

https://www.dotdeb.org/2015/07/04/mysql-5-6-25-for-wheezy/