Hi Martina! If you're going to San Juan, you definitely want to see Old San Juan and the Fort -- only a $3 entrance fee and well worth it. Have fun!

If you have time, you should check out Bioluminescent Bay http://www.biobay.com/ It's on the opposite side of San Juan. I went kayaking at night here and it was pretty incredible!

If you are renting a car - make sure you have change or dollar bills as there are a lot of toll roads. Also, buy a road map that has km markers because many exits don't say anything other than the exit number (which is the km marker). Knowing this would have saved me a lot of grief this last week! El Yunque Rainforest is super cool, but get there early because the gate closes at 6pm.

Fajardo is great The Conquistador Waldorf Astoria is great and you can usually get some great deals. I would suggest a car rental and drive there. Pretty easy to drive around in Puerto Rico

After you've seen the forts and the old town, rent a car and get out of the city for a few days. Listening for coqui frogs as you walk through the forest up El Junque (close to San Juan) is a great way to enjoy a little of the countryside. Also the Ruta Panoramica across to the west coast is an amazing drive. Chill out for a night or two at Hacienda Juanita in Maricao -- it's on a 24 acre plantation and has a good restaurant, then head to Ponce on the south shore and back along the east coast to San Juan. Enjoy!

There are a lot of great shops! and if you like purses there is a Coach Factory store!

Any and most all excursions are very cheap. Rainforest - El Yunque is free but if you want to go ziplining in the rainforest it will cost you about $100, Go to Culebra from Fajardo (top 10 best beach), Go to Guavate (best pig on a stick, lol), Aguadilla on the west coast (awesome beach), Cabo rojo lighthouse (also on west coast), Ponce (parque de bomba), bio-luminescent bay (either from Fajardo or La Parguera_, Lares (best ice cream shop with all naturally made ice cream).... So many more. Also, go on their websites and you can check out their local events and attend, which are fun.