How to play Civilization 4? [closed]

Solution 1:

The first thing you'll need to do is find a nice spot to build your first city with your Settler unit. You should also have a warrior unit which you will use to secure the surroundings, as your city is quite vulnerable at first, mostly if some barbarians are close.
Then, you will have to choose what to build in your city (as well as city organization). You can build units and buildings. Each of them with their advantages and drawbacks. use and abuse the Civpedia to know all the units.

You will also have to choose which path you will take on a science point of view. You will decide if you want to learn things which will help build better army units, units for discovering the area (land and sea) or for better buildings.
The main things is that there are several ways to win the game. You can choose which way you want to look after depending on the opponents, their proximity, their aggressiveness, etc... Then diplomacy enters in the game...

Yes, it's quite a lot to master upfront. Play some games on easy level, focusing on one direction (units, science, buildings, discovering, diplomacy, city management, etc). You will lose but you will learn!
And as I said before, know your Civpedia to know the units and buildings and how to have them available (science). Then you'll be able to decide which way you want to go and how to achieve the goals you will set yourself.
Then come back with more specific questions to master all the different aspects of the game.

There are also some videos available, like this one (and the following parts of the series) which shows the first turns and how to start a game.

Solution 2:

Go to Civfanatics WarAcademy and start reading up on strategies. They are neatly grouped by skill level and type.

Here is the most important points on running a Specialist Economy:

Definition of Specialist Economy:

A civilization in which the majority of research is funded by Scientist specialists supported by 1-2 farms or other high food resources. Since this approach tends to generate Great Scientists more quickly than other economies, another source of research is the lightbulb option.

Benefits Optimized regrowth of population from slavery/drafting. (Note: this sacrifices research until regrowth is complete.) Less danger from pillaging since farms are much easier to rebuild than cottages which have matured to towns. Independence from the Slider increases flexibility to divert commerce directly to gold for upgrades or to Culture/Happiness if the slider is used. More effective at higher difficulty levels (Emperor and above).

Limitations May require more micromanaging compared to Cottage Economy (CE). Specialists require supporting food resources or farms. In cases where food resources or fresh water for farms are unavailable this may be a limitation on early city placement. After Civil Service this becomes less of a consideration. Specialists can only be assigned if certain buildings exist (e.g. Library enables two Scientists). Caste System eliminates the restrictions for item 3, but conflicts with Slavery as well as other labor civics. This may later become critical if Emancipation is adopted by another civ, since the unhappiness generated by failing to adopt Emancipation can be a serious drain on productivity.

General Tips and Advice Prioritize food resources and farms in new cities. New cities only need Granary, Library and possibly Courthouse. Any other buildings are secondary. (This doesn't apply to Production cities which will be the same as for CE). You may drop the Slider to 0 when Alphabet has been researched and trade for any techs you do not yet know. This is to maximize cash for other purposes -- usually military upgrades or high maintenance costs due to conquests. However, it may be wise to keep the slider up at the maximum that is still generating a positive income for certain critical techs such as Literature and the Paper-Education-Library sequence (if there is no GS available for lightbulbing these). Alternatively, if dropping the Slider from 100% to 0% results in only a factor of 2 or 3 increase in the number of turns for your current tech, then it is about time to drop it. If it is much more than 3, you probably need to focus on getting more scientists up. Philosophy, Paper and Education are prerequisites for Liberalism and can be lightbulbed by a Great Scientist. Consider saving a GS or three for these techs.