Hi ! And welcome to AA !
This is a GREAT place to read and learn. If it weren't for AA my tank and my fish wouldn't be as healthy and happy as they are. I commend you for asking questions before beginning your (re)adventure into this wonderful hobby (some call it an addiction ! LOL)
The extra height of the 29G allows your fish more room in each "region" (upper, middle, bottom). As for which fish, that's too broad a question for me - did you have anything in mind ? a trip to the fish shops (LSFs) in your area might give you an idea of what you might be interested in.
To save you some time:
Bala sharks, cichlids, oscars, goldfish, clown loaches, and common plecos (to name a few) get too big for a 29G so save yourself some time by not looking in those tanks
Here's a great site to review some fish profiles:
http://fishprofiles.com/profiles/default.aspx?pnl=fresh
And
please, before you do ANYTHNG be sure to read the articles on the nitrogen cycle and on properly cycling your tank. You should seriously look into doing a fishless cycle - yes, its BORING to have an empty tank for about a month, but it beats the heck out of having to do daily water changes of up to 50% so that your fish are not poisoned by the ammonia and nitrites that will accumulate.
Here are the articles for you to read; please read them and come back with questions - we're all here to help !
Nitrogen cycle
Fishless Cycling*
*note: article written by saltwater keeper - the exact same methods apply to freshwater