Installing Industrial Craft for Minecraft 1.7.2
Solution 1:
The latest (experimental!) version of industrial craft is currently only available for minecraft 1.6 on the IC2 forum. Installation instructions are available here, but for new users it might be smartest to install something like the Feed the Beast launcher.
This launcher will do all the complicated things for you like install Forge and downloading the proper version of minecraft and various mods. This can be installed in a different folder than minecraft and they won't interfere with each other. Newer worlds aren't compatible with older versions so you'll need to create a new world for feed the beast I'm afraid.