Hi there, I've been playing guitar for over 20 years and I just wanna share something that I wish had been emphasized to me all those years ago.
This was before the internet was in full force, and my learning consisted mainly of tab books and general library books.
I couldn't afford a guitar tutor and any VHS lesson tapes cue violins playing
When I finally did catch up with the VHS lessons and later DVD lessons and the magic of Youtube etc, there was still quite a lack on the whole of what I consider to be very important.
Ok, ok ,what am I going on about?
EAR TRAINING!
If like me - you desire to improvise well melodically and emotionally. Then I think this is a crucial element for guitarists which (thankfully) only recently I'm seeing more of on Youtube and software etc.
I used to rely on tabs and later things like Guitar Pro, which don't get me wrong are great.
Yet taking the time to work things out both internally (Improvising that great widdlesome solo in your head etc) and externally (Cd's, Radio, etc) pay greatly.
I am nowhere near the level I want to be at, but by starting simply ( along one string like the High E string) and working out simple melodies is a great start. Here's some suggestions:
Standard Songs
Christmas Carols
Hymns
TV and Movie themes
Cartoons
Vocal Melodies (Iron Maiden was one of my favourites!)
I like to work out well known vocal melodies from the top of my head (internally), and also relating it to the scale it's derived from. (There's a ton of songs to go off when you're bored!)
Another bonus is - it's a lot fun!
Oh before I forget shout out to Steve Kaufman, who is a great guitarist and plays a lot of fiddle tunes - which are a great exercise for melody - short sweet and repetitive with a call and answer to them. There's a ton of MIDI tunes online for all the above. I play them on Windows Media Player and slow the speed down if I need to.
I would also combine this with singing for best results. You don't have to be a great singer (I'm certainly not!) but there seems to be a strong link between singing and the inner ear.
I hope this helps you with your playing.
If you like this I may add some more stuff (I've probably missed out stuff I wanted to say!)
Cheers and have fun!
Nate.