We did this last year - bought a condo in Naples. We have a timeshare in Ft Myers Beach and love the SW Florida area. DH did a lot of research before our vacation last Feb (2009) and found a realtor (Dean Rose) he felt he could work with. While we were there he looked at 8 places - none of them worked out, but it helped give us a better idea of what we wanted/could afford.
We finally purchased a 2-bedroom condo about 5 min. from the ocean, near shopping, restaurants, etc. We are west of I-75. The financing was a nightmare - we almost lost the place, so be prepared because it's difficult to purchase property in FL (at least it was a year ago). We basically ended up using a line of credit and buying it ourselves (no bank involved).
Once we got that all squared away, we found a management company and they rented it out fairly quickly. We consider this an investment in our retirement, which is still 10+ years down the road. But when we're ready to spend winters in FL, we'll be all set. Right now, the full-time tenant is helping us pay for the initial purchase.
Also, be prepared to deal with HOAs. That was a new experience!
I can't remember the name of the gated community we're in, but it's on Wading Bird Circle (maybe Palm River?). We paid under $100,000 for a place that a few years ago sold for triple that amount. It's not the fanciest place we looked at, but it's what we felt comfortable paying (and is certainly nice enough). We liked the location too.
Dh's dream is to buy another place in Myrtle Beach area for Spring and Summer seasons......