Base Placement

Picture
 This is probably the most important part of a successful game. If you fail to get off to a good start, you will be working to catch up all game long, everything is harder to get done in time and  you will probably lose. If you do get out to a good start, everything becomes easier, you are ahead of the race and you have a good chance of winning.  In addition, a poor choice of Base placement can leave you strategically disadvantaged. You could be crowded, contained, be unable to get into position to launch any sort of attack on an opponent's Base before you are attacked yourself.There are two ways to achieve the best Base placement.
                                                       Placing early and placing late.
 Placing early allows you to select the very best position for expansion on a map and you stand a good chance of collecting Peace money in Turn 0 if there is going to be any offered, but has the drawback of allowing opponents to place in position to restrict your expansion as they choose.
Placing late allows you to select the best position relative to all other players on the map, but has the drawbacks of possibly leaving you with a poorer position for expansion (on poorly balanced maps) and possibly missing out on getting some Peace Treaties in Turn 0 (in Peace games). Choose to place late in No-Peace games with balanced maps, which of course will only leave you with an advantage in placing late and no advantage for placing early.
Having said all that though, where is the best place to start on any given map?
Obviously, it will vary greatly dependant on the exact map you are playing. There are various kinds of maps that exist: Wreck, Tax, Resource, Barrier and Trick.

Always, always place where you can get a large number of resources and/or cities right away. You want to be able to make more money than anyone else on the map as quickly as possible. On the other hand, you don't want to have to sell off lots of units to get a lot of stuff as that impacts negatively on your overall income. The ultimate goal is to make the maximum combined profit in Units, Resources and Cities by the end of Turn 0.
Place next to Roads or Farms. Placing next to a farm makes it easier to reach a city straight away and helps your expansion in that direction. Placing next to a Road or intersection of roads allows you to expand faster and further. Both are good things.