Thats great San Jaun is really nice. Ive been down a couple of times. Here are a couple of tips:
1: Purto Rician Tobacco SUCKS-nasty stuff, this is what most of the street vendors in the square in old san jaun will be selling stay away and save the two bucks
2: There are some deals to be had around town as far as cigars go. there are several shops in close proximity in old san jaun- and they are very competitive and have good stock(they might offer you cubans but they are mostly counterfit be careful. I did find one shop that had the real deal but i can't seem to find the bussness card sorry.).Since the shops are so competitive you can play there prices off each other for non-cubans. I did and walked away with a couple of nice deals.
3.Check out the El San Jaun Hotel and Casino in Isla Verde. They are pricey but the casino and bar are cigar friendly, although they require a collard shirt and long pants to enter. ESJ is expensive but it has an ombance that reminds me of what havan must have been like in the days before castro. There is a cigar shop in the hotel but it is very expensive ($25 for a DC maximus rubusto

). buy them elsewhere.
Thats about it for cigars in PR.
The only other suggestion i have is to try to see more of the island than just San Jaun. The rain forest should not be missed and it is a short drive form the San Jaun. If you can make it, there is an island off the east coast of PR caled Culebra. The most beautiful beach you can imagin (crystal blue water and white sand). You have to take a ferry or a plane out of Fagro(sp?). but its worth it.
Also the metropole in Isla verda is great traditional cuban food.
okay so there u have it mabey i should have just recomended a book or something...if you have neother questions about PR let me know