1. Some miners have power supplies, some don't. If we take BITMAIN miners for example: S1, S3, S5 don't, S2, S4 do.
2. Usually to the router, some miners are USB but they don't offer much hashing power.
3. No, but knowing how networks work and basic computer hardware knowledge helps a lot.
4. Yes, I know Dogie has made a bunch of guides on a variety of miners. Here's the link for his BITMAIN antminer S1 guide:
https://bitcointalk.org/index.php?topic=355387.