i played civ rev and loved it so i picked up civ 4. now with civ rev being my only back ground im pretty lost. two big things seem to always hurt me.
Civ4 is a much more complicated game than civ rev from what I've heard, so try not to bring too many expectations from civ rev to Civ4.
1) people get mad about over crowding and become very unhappy very quick.
People call this the "happy cap". Especially early in the game when you don't have access to many happy resources, if any, managing happiness is an important part of the game. Try heading for the civic Hereditary Rule (available with Monarchy) - it allows you to use garrison units to increase the happy cap in each city so you can allow your key cities to grow larger.
There are various buildings and civics that also give happiness. I think there's an article called "Ways into happiness", written by Cabert I think. See if you can find that. EDIT: Here it is http://forums.civfanatics.com/showthread.php?t=189559
2) and what are the factors of an early game that would effect the maintenance cost in each place? does it vary buy upkeep cost of troops stationed there??
Distance from your capital and number of cities are the main things that affect the amount of maintenance. Number of troops has no effect on the city maintenance whatsoever. However if you have a lot of units you will be paying unit upkeep for your units from your empire's treasury. A certain number of units get free upkeep but after that it gets more expensive if you want to keep a huge army.
Code Of Laws is an important tech because it allows you to build Courthouses. Courthouses are one of the most important buildings in the game because they cut each city's maintenance in half - necessary if you want to expand to more than just a few cities.
To make sure maintenance does not cripple you, you'll need to make sure you do not expand too fast (building cities) until you have the infrastructure and techs to ensure your economy can handle it. Courthouses, the +1 trade routes that come with Currency, the cottages you can build with Pottery, etc. If you are running out of money you can consider building more cottages and make sure you work them so they will eventually become towns; towns net you quite a lot of commerce but take a while to grow.
mainly help me stop the overcrowding and keeping people happy. i use the avoid growth button, but dont i want growth? i cant build clay huts or something for them can i??
Most players advise against
ever using the Avoid Growth button because you're more likely to accidentally forget you left it on and wonder why your city never grew beyond size 4 and it's the year 1600AD already.
Try using the slavery civic, available with Bronze Working, and if you grow one or two past the happy cap, just "whip" them into a building or unit. If you opt to use the whip, just don't do it on the first turn of putting hammers towards something, as you pay an extra penalty for doing so. Rush things on the second turn (or later) of the build.