Well rather than point you to a link I'll just tell you here.
RW means rewritable. This means you can erase and rewrite data, or if you have software that can do it you can add and delete just like a hard drive as well, although it will be much slower.
R means writeable. You can only write once, so if it doesn't work or you change your mind or want to add something it's tough luck. And if the writer messes up it can be quite frustrating too, so it's usually worth the bother to use rewritables. The only thing to watch here is that some standalone players (DVD players, CD players etc) can't read rewritable disks. Almost all recent ones can, but it's worth checking.
As for the +/- debate, both really are much the same as each other, + writes slightly faster and is usually a little more compatible overall but again you just have to do your homework and make sure it will work where you need it to. And again, almost all recent players read both but you must check. The same goes for the DVD writers themselves.
The only one you missed out is DVD-ROM which is a bit of an oddity. It's really more of a storage device for computers and isn't worth the bother for most people as it isn't very compatible in such a widespread way as the others.
As for software, Click to DVD is OK as far as it goes and if you're happy with it and does everythin you need then worry not. If you need more and want to look elsewhere then Nero is usually considered one of the best, there's a demo here when you're ready to give something a try. It's a 30 day trial so don't install until you have a writer.
