Cheap, stable, and light-weight. General rule is with tripods you can have any 2 of those, but not all 3. ie if you want cheap, it'll either be stable but really heavy, or light-weight but not stable. When first starting out I bought my wife a tripod. It was a cheapie, but the head and connectors are plastic and can't take a lot of weight.
What camera do you have and what lenses? The weights you put on it are a factor too. Also what type of photography are you intending to use it for? Landscapes, or holding camera steady for timed self-portraits, or something else? There are different types of head on them - ball heads, pano heads, geared, and so on.
Also need to consider compactness. Some might fold up nice and small for travel, others have longer segments on the legs.
Here's a great, comprehensive thread on considerations that I recommend reading:
http://photography-on-the.net/forum/...d.php?t=740131