heh OK didn't know you were starting from such as disassembled state.
On the big posts for the solenoid (which is just a big electrically-actuated switch), one connection is for the starter lead, the other connection is for the positive battery cable, which connects directly to the positive battery post. Do you have this?
For the small connections to the solenoid, runs to the starter button (yellow+red) (which provides ground) and the other connects to +12V from the harness (black). Looks like you've got those hooked up right, but I would recommend you get rid of those wire nuts and use something better (assume you're just using them for debugging).
A k5 should have a fusebox with three fuses, a 15A main fuse, a 7A headlight fuse, and a 3A tail light fuse. This connects to a modular connector under the left side cover.
mystic_1