Well, if you're just fishing for trout now just make sure to check the regs if you're keeping them. As for steelhead, you're going to want to invest in a decent 8'6 to 9'6 rod and depending on your preference a spinning or baitcasting reel. Sounds like you're comfortable with a spinning reel since you mentioned spinners. Anyways, then you'll want to spool on some 12 pound test at least and learn some knots like the egg loop. From there, get size 2/0 hooks, good quality ones. Then you can get bait such as sand shrimp, prawns, or eggs. The easiest way to start steelhead fishing is either float or spinner fishing but your best bet in winter would be float fishing. These are just the basics hope it helped.