Minnows...

Not for steel I don't. Too much of a waste of time and usually if they are hitting minnows you'll hook'im even when the minnow is hooked through the lips or eye sockets. Sometimes when there is little or no current like up there now I'll hook the minnows through the back and free float them with out any weight and let them swim where they may.
 
Just my two cents.

what size minis are best for steelies. lil crappie size or bigger?

Rsquared is correct in his explination on the use on minnows. Myself I prefer emeralds and fatheads about 2 inches. Last week and the week before when I bought shiners I got some about 4 inches.....those are bass and walleye size. With no current to contend with you can just about free float them or a very small amount of split shot about 18 - 20 inches from the bait just to get a slow sink. As the water gets colder I've often used dead or salted minnows and just dead drift them through the current and along the bottom with some extra weight. Some of my biggest hens have been caught on salted minnows.