The Borderline is one of the places that I'd check out to see who is playing. You might want to check out a new venue called Kill All Hippies. And then there is The Metro. For a flashy night, you may want to go to Electro Clash. Not sure I'd like it myself but it all depends what you're up for.
For a night in a pub without a band, a lot of my friends hang out at The Social in London. It's owned or run by Heavenly records which is the UK Astralwerks label. They opened it up to showcase their DJs and music. Nothing special but the music should be good. For what it's worth, Chris Martin and some other UK celeb came in the other night while my friends were there.
There's also a place that I've heard some things ahout called something like The Elephant Bar. (Maybe it's another animal or a fish.) It's a pub but I think they may have very small acts at times.
As far as record stores, you may want to stop in Sister Ray's. May not have bargains (not sure) but should have a broad selection and many hard to finds.
When are you going? I know that Explosions In The Sky with Trespassers William will be playing a show there soon. Think it's a weeknight.
