This comment was left on the blog-post I made about Abandoned cats. I think the information is really useful, so I've turned it into an actual post! Thanks to Sarah for writing it and giving me permission to include her comment here! ;-)
Good for you! We got asked by the local shelter to take on 6 feral kitties whose feral mum had done a runner, so they could be socialised enough to be homeable [I used to work there so I'm muggins] - we ended up keeping 3. Kittens aren't going out like they used to, not in this economic climate. And they are expensive to neuter and have vaccinated [specially round here where feline leucaemia is endemic and an expensive extra vaccination]. The RSPCA DO offer a free neutering service though, and sometimes so does the Cat Protection League, or at least some help with it. It's always worth while asking! We prefer to save up and stick with our own vet but we have a large enough house that over winter it's no hardship for those waiting to be done [and I like girls to be about 7-9 months anyway so they're a bit bigger].
Can I mention that ebay gives the opportunity to donate an extra pound or two to cat shelters when you buy through them. It's called Cat Chat