Welcome back. I just returned a couple weeks ago as well.
You can use 9X9 and 7x7 if you wish, but I find them hard to use on some maps, and I generally don't like their appearance. Specifically because I like to have my housing on the outside of my loops so I have simpler labor access, among other reasons.
Housing block examples are available from many locations. Searching these forums will give you a ton of options; a lot of threads were started by me and then discussed between Brugle and me
ad nauseum.
But you can get started with the blocks listed by Joshofet in Reply #3 of the list of most useful forum threads sticky.