I remember starting my first contest on another blog. I use Excel for update the sponsors on the list. I also used it to check on who is taking part in my contest. You can find out how Makoy use Excel Drop Down List and Validation.
If you are holding a contest at your blog, you will find this info useful. Makoy's contest is going to end on 15 March, you can still take part if you are interested. Makoy's blog has got other useful info for you to find out. I am sure you like to find out how he manages his four blogs!