Eusing is a good program to use, which I've found is a bit more in-depth than others.
Also, you can use CCleaner to wipe off some of the erroneous or redundant entries. While not as effective, it is a safer option.
Be sure to backup your registry whenever prompted, in case you delete something that you need. Also, comb through the suggested items for deletion; unchecking anything that you are unsure of.