1st Up David - Welcome back to vinyl - there'll be no turning back now

2nd up congrats on a nice front end - I ran a Black on my Sondek for a while - Great Combo

So onto your question - the great news is if your general preference lies in 70's early 80's Classic Rock (like me

) then there is still a huge amount of good quality, keenly priced vinyl out there.
For $1-5 it's never gonna break the bank just taking a punt on something you're interested in - I've got some great finds doing this.
I still listen to the Classic Rock radio stations and even after numerous years of exposure to this stuff there's lots that continue to be new to me. It's a great way to do your homework

The "What LPs have you listened to recently?" and "Catch of the Day: Vinyl You've Recently Bought " threads here are also an inspiration.
There's always new bands mentioned that I need to go and look into.
My preferred resource for doing this is
SPOTIFYThis is free and you can hear whole album if you want to.
I typically use it just to get a quick flavour - it's added to my want list and I keep my eyes peeled at Record Fairs and/or Stores.
I also use
DISCOGS as my primary on line buying resource.
I've found the sellers (generally) are much better at grading their vinyl than the bay, but I still assume it's a notch down on their claims so as not to be disappointed.
This is great as you can dial in your specific wants and search for availability around the world - the US and Europe are very well represented by vendors.
Also, once it's in your want list you get notifications when new sale items are added.
Final bit of advice is do some digging on the vinyl forums on how to spot good and bad when it comes to used vinyl.
Some quick tips from my side
If it looks clean but the vinyl is a little dull then it generally sounds dull, probably played on a poor rig in the past - I keep away.
Look for "spider" marks around the spindle hole - lots of these tend to indicate many plays - Again I tend to avoid unless it's a long yearned for item or very well priced.
Obvious one is avoid anything that is visibly scratched, regardless of how minor they might appear - generally even the slightest of scratches causes pops.
Finally - don't be too frightened of dirty discs that are scratch free - this tends to happen if they have been sitting around for a long while, many of which may be unplayed. These can be cleaned - check out the many threads on this (my method is identified in my web page).
Cheers
Dave