I use a reasonably stiff brush to take dry mud off (cleans brake gunk off of wheels as well). Then wipe over the frame with a bit of GT-85 and kitchen roll and finish with spraying with furniture polish (
Morrisons cheap one). The polish seems to make it harder for mud to attach itself to the bike meaning that it's easier to clean next time as well
For the chain, look up the mickle method.
Oh, and I also keep guards fitted on my bikes almost always