I'd do what schnell said. Take a look at the Extra Dry and the Pedro's bio-degreaser. I rinse the bike under a low pressure hose and use a soft cloth to wipe down gunked up areas. Just be careful about where you point the hose. You can use an attachment on the hose to blast things off the bike, but be aware that you shouldn't point it at the bb, hubs, or headset, as the spray can push debris farther into the bearings of these assemblies. A soft cloth and careful use of the bio-degreaser and hose should have your bike sparkly clean safely and quickly.
-Moab
P.S. - One way to lower the danger of contaminating the bearings/grease in sensitive areas is to use a house without an attachment on the end. This greatly limits the amount of pressure that is put behind the water.