Beginning reading SF
First off buried in the depths of the humungous BBC site is the books section and inside that a genre section and inside that as Science Fiction readers guide. The guide is dated by a couple of years but still gives some great recommendations for the classics, a few of the cyberpunk greats and some more recent reads. If you don't know where to start here is as good a place as any.
Another great place to find some of the classics is the Millenium SF Masterworks list. They started reprinting classics in the year 2000 at the rate of 2 a month and now the list is very impressive. It'll take you a while to work through it now, so get started.
The The British Science Fiction Association (BSFA) site also gives a few suggestions on where to start with a few different members giving their recommendations, some new, some old, all good.
Of course new Science Fiction is coming out all the time so you also have to keep an eye out for recent stuff. I always find that the Amazon Science Fiction page is worth visiting now and again
So there you go, some ideas, now get reading!
