All good advice so far. I'm also new, so my advice should be taken with a grain of salt. I have a terrible instructor, but he's me so I can't fire him.
Here are a few things I've done.
For chord changes, write out all the chord changes in a song. If the progression is G- C- G- D, then you have the following changes
G to C
C to G
G to D
D to G
Once you know all the changes, practice those chords. Once you know the chords pretty well (meaning you can get them without much delay and without having to think specifically where each finger goes), then think through how you're going to get your fingers from one chord to the other. I find it helpful to worry about what my index finger is going to do, the others just kind of fall in line from there. Then, do what you just thought about (i.e., the chord change) over and over and over and over and over. Then try it with strumming a steady beat. It doesn't have to be fast, just steady. Once you feel fairly confident with each chord change, then you're ready to strum the song through. So go ahead. Strum the song through. Sing it in your head or out loud, but bear the melody in mind. I find it useful to sing out loud, though no one else seems to like it much.
Another thing that I am noticing that I need is the scales work. I've just ordered a scales book and will begin practicing them. As of right now, I'm a strummer only. In a year, I'm hoping to be able to pick out some leads as well. Playing lead riffs is all about arpeggios (playing the notes of the chord in certain orders) and scales. Knowing what notes can be played in what "keys" is key to playing the right notes, and I figure that scales are the best way to learn which notes are in which keys.
- Zurf
Granted B chord amnesty by King of the Mutants (Long live the king).
If it comes from the heart and you add a few beers... it'll be awesome! - Mekidsmom
When in doubt ... hats. - B.G. Dude