I've just finished listening to a set of lectures by Greg Bahnsen on defending your faith. First class stuff. Get them and listen to them - I'd post them for you, but they're copyright!
So you'll have to buy them yourself, but they're well worth it - somewhere in the region of £1 each. There's ten of them, but why not buy the first couple and see what you think.
Here's a suggestion - buy the first two and get a group of you together and listen to them, and talk about it.
You'll get them here