THIS IS TAKEN DIRECTLY FORM THE TRIBAL WARS MANUAL, FOR A MORE DETAILED GUIDE SEE BOTTOM OF PAGE
In the beginning you mostly need one thing: Resources. The Timber camp cuts wood, the clay pit collects clay and the iron mine produces iron. The more you expand those buildings the more they produce. In the first few days it is recommended to heavily concentrate on resource production.
While you are concentrating on your resource production it is important not to forget to defend those resources. You don't want to lose all those resources that you worked so hard for to a plunderer. One way to protect yourself is to build up your hiding place. The bigger the hiding place, the more resources are safe from attackers. Building up your hiding place is especially important if you have bigger players around you. It is also recommended to build a wall. Every level means that an attacker loses more troops and makes it unprofitable to attack any further.
After you have secured a good base production of resources you can start building troops and trading. In the barracks (Headquarters level 3 needed) you can start recruiting spear fighters. Those fighters are not usually good attacking troops but they are very valuable to do early raiding attacks on very small villages and players.
If you prefer to trade, you should build a market. (It needs headquarters level 3 and warehouse level 2). Then you can see what your neighbors are offering and trade away excess resources. You can also create your own offers.
You should also look around your area to find a good tribe to join. It is always easier to fight and defend in a group. It is also a good way to meet some nice people...
For a more detailed guide which I believe helps a little more, see Startup Strategy
Or you can look at this outside link: http://forum.tribalwars.net/showthread.php?t=6827