So, I've studied some theory and I can read music on a basic level now. I continue to study theory every day, and I think I'm doing well, but I'm looking for some tips on sight reading the notes on guitar and bass.. It's looking really hard, but I really want to learn it. Is there any way to go about it that isn't confusing or possibly unsuccessful? I'm willing to put the time in, I just need some good methods.
There's three angles to this:
1. Being able to read music (know what the notes are, how the rhythms will sound). You can do this just with singing, or clapping rhythms. Of course, with guitar and bass, you have two clefs to learn.
2. Being able to find those notes on your instrument (in all their possible places).
3. Being able to do that on sight, i.e. at tempo the first time you see the music. This is real "sight-reading".

I'm guessing you're somewhere in stage 2. That's a technical issue, not a reading issue. You need to learn your fretboard, to be able to put your finger on every (say) C# note in turn as fast as your fingers will let you.

You don't have to be fully up to speed on stage 2 before working on 3, but obviously you can't properly sight-read if your fretboard knowledge is not fast enough.

But there's no real "method" here, and the only materials you need are a steady supply of notated music that you haven't seen before. (To keep practising the same pieces is no good, because then you're learning them, not sight-reading them.) You don't have to buy any sheet music, there's plenty free online - it might not be the cool music you like (because that will probably be copyrighted), but that isn't the point, right?
There are like a million books for sight reading on specific instruments. I'd pick one of those up, as well as just make a point of learning music from the staff.

I agree with jongtr - it sounds like you're lacking fretboard knowledge, which will of course make reading impossible on the guitar. And theory is pretty much useless if you don't actually understand how it sounds and works on your instrument. I'd recommend moving your focus to the guitar and learning music, then come back to the theory when you have a knowledge base upon which to apply it.
Last edited by cdgraves at Dec 1, 2016,
Sight read semi-regularly for years and you'll be a pro.

But you'll never do it without fretboard knowledge. Defer to above posts for good advice.
"There are two styles of music. Good music and bad music." -Duke Ellington

"If you really think about it, the guitar is a pointless instrument." - Robert Fripp