Ok so why are you coming here? Business or pleasure? You need to stay on the same side of the bay that the business is in. The economic engine of the region is in Tampa, not across the bay. Oh as for the debate as to which is better...screw St. Pete
. sure they got the beaches and the dali museum, but thats about it. Tampa has everything else. St. Pete, rather than appreciating what they are and what they have, is always in a competition to be better than Tampa, but never quite makes it. And its sad cause St. Pete is very much old touristy Florida. Its got some cool quirks about it and I enjoy visiting. Now for the definitive visitors guide, if Mimic can dig up that PM I sent her from last year, and if she can post it here (she has my permission) it should help you out quite a bit.
As for the best centralized location, a hotel in the Westshore business district would be the best place to stay. It aint gonna be cheap, but it will be centralized. From there you can pick up the interstate or the Veterans express way and get to anywhere in Tampa or St. Pete / Pinellas county. As for traffic, it can suck, but no where near as bad as places like Houston. But the nightmares usually exist during during rush hour and it becomes bearable. While you are down here in January or February, you might want to catch a Tampa Bay Lightning Hockey game. The fishing isnt the greatest this time of year, but get a good guide who will keep you in shore and you can still do pretty well. In Tampa you check out the Florida Aquarium and the SS American Victory (a restored WWII victory ship), or visit Ybor city and take a historic tour that will tell you about the Italians and Cubans that made Tampa the cigar capital of the world. Learn about how the 1st Cuban revolution was started and managed out of Ybor City by Jose Marti. Visit the University of Tampa (The former Tampa bay Hotel) and check out the awesome architecture and learn how Teddy Roosevelt and the rough riders encamped and then departed from Tampa for the Spanish American war. Oh and if you are coming down in February, hold on to your had and partake in our celebration of a mythical pirate who invaded the city...The Gasparilla Festiva. Its a drunk fest and a blast. The night parade is and the day parade is a must see. Why not hit Busch Gardens for some fantastic rides and a great zoological park. Also check out Lowry Park Zoo. We have awesome Cuban food. Check out La Teresita for lunch at the corner of Himes and Columbus Aves and get a cuban sandwich. Then make sure you stop at the Columbia Restuarnt in Ybor city for dinner one night and try the Paella. Its great. The nightlife abounds. Best bets in Tampa for a tourist will be Ybor city and Channel side.
Over in St. Pete, there is the dali museum, the beaches, the pier, El Caps (best damned burgers in the bay).
And thanks, FrontLine, for your excellent suggestions! 
