Title. All my life I've fished for bass and gar and crappie in small creeks. I'm going to Northern Wisconsin for a couple weeks this summer, and I realized I have no idea what bait to use. My go-to is a medium size hook with a white worm. I've heard they like spinners? It'll be in small rivers if that matters.

Also, do they have teeth? Do I need a leader? Can I fat finger their mouth or do I need a jaw holder?

I havent been up that way nor have I fished for trout in years, but the small streams I have fished here in pa has strictly been spinning or meal worms. Never got into fly fishing, but I used panther Martin or rooster tail spinners without sinkers. I have a couple 5'6" ultra light rods and reels, I take 2 because I have broke them. Trout do have teeth, but generally the average size here it's not much. I more less scoop them up vs grabbing  there mouths like bass. Just get a good vest, pliers, lures, smaller hooks and sinkers if you do use a type or meal worm or power bait. Couple rod/reel setups, and a good set of waders if you dont have them. Also get the normal pliers and line snips if you havent. Trout here are usually around 12" or smaller, there are some bigger ones but it depends on what's stocked. Native trout are about 6" where I use to fish.

What he said.  Panther Martin type spinners, get several different colors.  Small swivel snaps are nice. No special leaders needed, 6-8 lb test line will be plenty.  Get the spinners small, 1/8 oz.

You’re not fly fishing, but some guys like a small, clear bubble and a fly 3’ behind it.

Small trout have small mouths, and you’ll catch your share of small ones.  Some decent hemostats are great for unhooking trout.   You may even have to cut one of the treble hooks off the spinners.  They can be a bear to unhook without killing the little fish.

Nothing wrong with a little power bait or salmon eggs on a single small hook.  Get some small splitshot too.

If you're releasing them they are a bit fragile.  Lose the treble hooks and crimp the barbs.  If they start bleeding out of the gills, they're toast.

Panther Martins, Thomas Cyclones, Mepps, Small Rapalas, will all work.

Not enough teeth to fray leaders.

Mepps French Spinner

Trout have small but sharp teeth, like a rasp (unless it’s a pretty big trout)
After a day of catching them, your thumbs will be all shredded up, but not bloody.
Kind of a neat reminder of your fishing trip for the return to drudgery when you go back to work.

Luhr super Duper in the smallest size. I use silver/red or white/red.

Do not grab them by the jaw, they are fragile.
Along with the other recommendations, try Kastmasters too.  Smallest size.
Joe's flies are great too:  https://joesflies.com/
I'm not sure of the water you are fishing, and the trout sizes, but around here I don't go over 4lb.  I also use flouro.

@pagoda

What tradeoffs have you seen with fluoro?

I still use mono, but I'm thinking about going to fluoro.

All of this, plus  vibrax spinners.  Salmon eggs, earthworms, and power bait can also work.

All of the above work well. Small Hopkin’s spoons are also really effective. My go-to’s...

@timthemedic
I haven't noticed any real differences.  Feels similar, knots similar, seems to have similar strength.
I just have to hope it is more transparent under water.  
I DO have to pay more for it, though.  But fishing line is probably the least of my expenses.  

ETA:  Oh, and Trilene XL Mono @ 4lb is .20mm diameter.  Trilene Flouro is .17mm.  
So a bit of a bonus there.

It's more sensitive than mono and doesn't stretch as much. I use flouro leaders on my gear, which seems to work better at fooling the fish.

Thanks, appreciate the response.