I visited Puerto Rico about ten years ago. The thing that amazed me the most was that you land, and your cell phone works without roaming, you don't have to change money, and once you drive out past all the Bed Bath and Beyond and Walgreens you have access to all these beautiful beaches and the rainforest.
We stayed in the El Yunque (pronounced El Junque) rainforest for a couple of days and I really recommend that area for hiking. There are a lot of local beach options, but we took a very short flight on a tiny plane to Culebra (recommended by a Puerto Rican friend), which had the most spectacular white sand beaches with crystal clear water that I've ever seen.
I also remember that we kayaked at the bioluminescent bay in Fajardo and it was one of the most amazing experiences I've ever had. There are these tiny organisms in the water that light up when there's motion, so every sweep of the oar results in a trail of sparkles in the water. You have to make sure to go on a less moonlit night for this. One of my friends who went recently said that they no longer let you jump in the water (due to sunscreen and other chemicals on your skin), but that it was still incredible.
I know very little Spanish and we had no problems there. They have a good tourist infrastructure and you'd also have no problems driving (although be careful on the dirt roads in the rainforest-- we got stuck in the mud and had to get pulled out!). You have to be more careful around San Juan (the touristy areas like Old San Juan are safer), but we felt completely safe once we left the big city.