Get some WD40, Teflon spray, drive-chain spray and some rags you can use to polish your bike with. First clean your bike untill it shines, use WD40 to get the tougher dirt off. If you look at the chain you can see it's completely dry and it may already have started rusting. Snow, ice and rain wash the chainlubrication off and will make the chain start to rust wich will cost you a lot of engine power. Drown the chain in WD40 and use a rag to wipe it clean, the rag will be blackened by the dirt. Now put your bike on the center stand, start the engine and drown the chain in chainspray while the chain runs over the sprockets. This'll protect your chain pretty well, add a little chainspray every couple of days to keep the chain lubed. Polish all the metal parts (inc. painted parts) of your bike with teflonspray. This'll form a protective layer over the metal parts and will make all the parts shine really nice (sort of like a waxcoating). Just wipe a cloth with some teflonspray on it over all the metal parts every couple of days to keep the parts clean and shiny.
If your bike is really dirty, I mean half-an-inch-of-black-goo dirty, than DON'T clean your bike. The black goo wil form an excellent protector against the elements.