The off season is a great time for cleaning your golf clubs, and dont forget your golf bag give it a thourough cleaning also, especially inside the pockets, including any other repairs and maintenance on your equipment. It's also a great time to take inventory of what you have, what you don't have and what you'll probably need to replace for next season.
When it comes to golf club cleaning
If you want to clean your clubs yourself, grab a few things and get to work. You'll need a bucket, some clean clothes, a tooth brush or something similiar, some mild dishwater soap and some elbow grease.
For your irons: Important Tip: Do NOT submerge your club heads into the bucket of water above the ferrules!!!. Make sure you have good head covers for your woods. A very good set of covers are NCAA Set of 3 Headcovers - Various Teams
For newer golfers, the ferrules are those black rings where the club meets the shaft.
Okay, here we go. Put some warm water into the bucket, along with a dab of soap. Don't use very hot water. Hot water can loosen your ferrules. Also, you only need enough water to cover the heads of your irons...not the ferrules!
Put your irons, club face down, into the bucket and let them sit for a bit. When you're ready, take one out and using the old toothbrush, give the grooves a nice washing. There is a very good product worth looking at called, Denali Clubtub Portable Club Cleaner