well just one question, can you clean it with the motor out? if so, that's the best scenario, you can literally get every crack and cranny cleaned alot easier like that. you could also do a little "touching up" with it out if you wanted to respray the engine bay.
if not, don't worry, you just need to watch out for a few things. before anything, cover up your dizzy real good, and the tps sensor aswell. if you have a open air filter in the bay, cover that also. now you can get to the cleaning. Simple green is a great degreaser that works great, and you'll need a few rags, a small-med. size brush or two, and your ready to go.
simply spray the degreaser on it, more heavily where it's more dirty, and let it sit a bit. then give it another pass with the degreaser and get your rag out, wet it a bit, and start to wash everywhere you can. once your done, use the brushes to get the grimiest stuff off, and then you can rinse it. give it a nice decently powerful rinse and then get some towels and dry off asmuch as you can. (i use my air compressor to blow off the water it the tough to get to spots). then take the covers off the dizzy and tps, and you can start the car. run it for a minute or 2 with the hood down, and then you can turn it off. the heat under the hood will steam out any other water that was under there. ALL DONE!
if you want now, you can even wax some spots in the bay(so dirt and dust doesn't stick so easy) and then use some silicone(tire shine) on the hoses, rubber lines, and other plastic bits under the hood. before you know it, you'll be ready for a car show
