GSV,
I agree with wwpmi and say do not waste a single moment in SD. WAY over-priced for VERY little anything more than maybe an half-interested dance while you have to sit on your hands.
Go to TJ.
Take your passport and maybe $250... $300 at the most (you could get laid twice, drink 2 beers and pay for cabs and trolley for $175), but NOTHING ELSE except your hotel room/house key!
Take the SD trolley ($5 for an all day pass) to the very last stop and get off right at the border. 5 Min walk over the pediestrian bridge, then though the revolving gates and you will be in TJ. Taxi stand is there through the 2nd gate and for $5 you can go pretty much anywhere in TJ. Just ask for Hong Kong or Adelitas. Politely decline if they try to sell you on Club Amnesia... it's more expensive and the girls are the same.
Go straight to HK if you want more of a strip club atmosphere, I usually start out there myself for the eye candy and the crazy ass shaving cream shows they have. For your first time, I would do as others have suggested and leave in the early evening so you can arrive at the club before the sun sets (30-40 min trolley from downtown, 10 min walk over border, 5 min cab ride).
That said, realize that while both clubs are open almost 24-7, the girls mostly set their own hours, so the hottest ones will be on Friday and Saturday nights after 8pm, and many not on until after 10pm. It gets very crowded both of those nights, but there are also a LOT of women. And if you can go on one of these nights I will promise you that you will see some women that just drop your jaw at how fucking hot they are... and then it hits you that you could fuck them for $60 + $12 for the room. And $60 is the going rate, some of the hotter ones that think their shit dont stink may try to upsell you, but don't fall for it. Sunday-Thursday starts out very slow with slim pickings from the girls, and it picks up as the week goes on... peaking on Fri/Sat nights.
Good tip: always negotiate everything before you go upstairs. Basic procedure is a quick covered BJ followed straight sex.
Finally worries about STDs are understandable, but I've never had an issue. Most of the girls are VERY clean and VERY serious about safe sex only. Others might do anything for an extra $20 on top of the regular rate. Old/ugly ones will offer uncovered acts and extras on top of extras, and often for less than the going rate of $60. It's up to you what you want. My advice is to skip the super hot model-type girls (unless you just want a trophy fuck) and go for the cute ones with a fun personality or disposition as they are always much more fun upstairs.
I'n headed down there first weekend in June and really looking forward to it. PM if you want more specific info, or read some of my previous reviews of both HK and Adelitas.