My 9 year old son and I made a trip up yesterday, and things are way behind for this time of year. Supposed to get some good rain in Erie tomorrow and Thursday which should help. About the only game in town right now is lower Elk, from the lake upstream to the Cascade hole, or the wall in the Walnut Channel. Didn't fish at Walnut, but stopped by to look and NOBODY was fishing in the project waters, which should tell you a lot. A few guys in the Manchester Hole and in the Chutes.
As for gear and tactics, a noodle rod is a big help. All the tackle shops up there sell 'em. Can get one as low as $30-$35, and I've been using those for years. I use 6# mono on my reel, and ALWAYS run a fluorocarbon leader. 8# most times, but sometimes 6# or 4# is necessary, as it was yesterday. Some guys like fluro for their main line as well, so that you don't have to re-tie leaders when you break off. Either way, I would make sure the last 4' of your line is fluoro. Use a real small barrel swivel or a surgeon's knot to connect fluoro to mono.
I never use a hook bigger than a 16, and sometimes will go down to 20. Didn't have any 20s yesterday, but wish I would have. I think it would have made a difference.
Don't use the split shot you find at the big box stores in the general fishing section. The box stores with fly fishing tackle usually have Black Bird brand split shot. It's a duller color and much smaller. I use size 2 and size 4 depending on flows and water clarity. Sometimes one or two is enough, sometimes 4 or 5 are necessary. It will depend on your bait and water flow.
As for baits I use with that set up, I love the 3" Berkley Power Worms. Bubblegum pink has by far produced more steelhead for me in the past 5 or 6 years than any other bait. Yellow and White are also good. Sometimes in stained water chartreuse or orange is good, but I always use pink worms first. Emerald shiners are a good choice, as are single eggs that you can buy cured at bait shops there. Egg sacks can be good too.
Most of the time, I'll pin my bobber (I use the small foam ones, with a slit in the side and a peg) at least 6' above my hook. Sometimes as much as 8' depending on water depth and where the fish are holding. Sometimes 2 or 3' if I can see that fish are in shallower water or holding in the middle of the water column. Start with a presentation where your bait ticks the bottom from time to time, and adjust from there if that's not getting any looks.
Jigging can be effective too. A lot of anglers there have success with hair or maribou jigs. When I jig, I like to use Gulp Minnows on a 1/32 or 1/64 oz jig head. If you fish in the lake, spoons can be good. If you start chucking spoons in a creek, you're not going to make many friends around you.
If you wait a few more weeks (assuming rain amounts return to something more normal) fish will be well spread out along bigger streams like Elk and 20 Mile. They will also get into the smaller streams as well, and you'll have plenty of options to get away from the crowds. It's tempting to fish lower Walnut because it often has a large amount of fish concentrated into a small area, but it's a zoo, even on weekdays now. However, you can learn a lot by going there and watching what others are doing and asking questions.
As others have said, if you have any more questions, feel free to send me a PM on here. Be glad to help you out.