wallzer,
First of all, welcome to EFN!
The Ring Worm is a pretty versatile bait. It can be used in many different ways and situations. My personal favorite is to thread it on to a jig head and pitch the shallow’s. This bait is also very successful when vertical jigging aggressively. The best color? They are all good at one time or another, just experiment until you find what the fish want. As general rule in clear water stick with the lighter smoke and salt and pepper colors. Darker water, the chartreuse, lemon lime and to tone colors produce well. This is just a standard rule of thumb to follow. There has been many a days were just the opposite will apply. Don’t be afraid to change it up a little and see what happens.
Jig size? Just depends on the given situation. If you are going fish them aggressively go with a heavier jig to give you a faster action and a more distracting thump. Lighter is more of a finesse way to go about it. My personal favorite for the river are 1/8oz and 1/16oz. Jig color is not that important to me when fishing with the ringies, I guess it has never really mattered that I have personally noticed.
Make sure we get a report when you make it back home. Good fishin’!