I went to Robin Jacobs for maternity massage on my first one. Found out there are several in the area. Massage Envy on 4th street gives them. First visit is only $39 for a full hour. There is also Tranquility Day Spa (by Bay Walk), JCON Salon and Spa, or Stress Relive Clinic on 4th St.
If you have back pain, go see Dr. Stan Pierce of Pierce Chiropractic (62nd Ave N, by St. Pete Christian School). He was the only one that gave me relief for my back pain. It's non invasive. I also suggest making sure you are in alignment as it keeps your pelvic area in alignment and makes delivery easier.
Check with your hospital for infant massage classes. I know Morton Plant offers them. Some one also sent me a viedo on infant massage that came with a onsie showing all the places to massage and how each area offers relief for various problems (such as gas). I have lent it out or I would give you a name, I don't remember who I lent it to. You might check with the libary, maybe they have a book or video. If you a higher a doula she can probably help you with that as well and ask the massage therapist you selt on. Some will show you how to massage your infant for free.
Good Luck!!