I heartily recommend "Absolute OpenBSD, 2nd Edition." The answers to (almost) all of your questions, and others that are bound to come up, can be found there. It's written at a nice intermediate level.
Also, is it necessary to partition your disk into smaller pieces? I mean, I can understand why this could be important. But in my experience, I have had many more issues with small partitions than one great big /. Usually by way of tinkering with sizes to be big enough, but not too big. It seems to be never ending agonizing unless the workload is known fairly precisely. Yes, you would need a (C)ustom: z (<- erase table) a b (<- add a swap if you want, customarily 2 * ram of system) (accept offset) (enter size, e.g. `8G' ) a a (<- remainder for /) (accept offset) (accept size) (accept default format) ( mount at `/' ) w q and move on to better things in life. (You can back up to another volume with rsync, too!) Best regards, Eric