Linux filesystems are usually ext2, ext3, or resierfs.
"swap partition = doubled ram size" is that right?
This pretty much was the formula for back in the day when physical memory was expensive. Now, it's not. I mean, if you have 2 gigs of ram on the machine (and your machine is a simple web server), then it would be a complete waste of space to make your swap 4 gigs. Right?
So, pretty much it all depends on what you are doing with your server and how much ram it has in it.
are there rules how to make partitions
Not really, u make your partitions based on what you need. You can make 1 single partition '/' and be fine with the install. For me, I like to separate '/', '/boot', '/home', '/var', and '/usr'.
Sorry, I don't know of any tutorials at the moment besides http://tldp.org
but just install it and have a crack at it. The more you mess with your system the better you get a feel for how it works. If you run into problems, then post them here and we would be glad to help!