[supramacist]

I can't tell you what to go buy.

There are so many opinions in this thread...., and all of them are probably good ways to go.

You will definitley want 1 or 2 small brass bristled brushes. Probably a roll of the classic red shop towels.

Some kind of engine degreaser or grease and rust penatrent.
Which ever you decide, get enough to do the entire job.
If you purchase to much you can either take it back or save it till you need it.

I still say pb blaster, but I can see where brakeclean would work as well.
The big thing with the blaster is there is absolutely no water in it.
If it gets on your clothes you get tired of smelling it, but it doesn't irritate your skin.

Mothers is good but isn't really for cleaning the engine bay.

Scotch brite pads. For those pesky metal tubes and what nots.

Last but not least..., your girl. because you're going to find that you need smaller hands to get into some of the places your dick skinners won't reach.