My new site for guitar lessons :D

Nice site, good beginner level stuff, alot of sites don't start basic enough, yours does this well.

As regards minor chords although a beginner shouldn't be bothered with the technicalities you should emphasise that minor chords sound softer, more mournful than major chords. Play E A D it's upfront, it's ballsy, it's confident. Play Em Am Dm and you have a ballad, a love song, a song of regret... (actually there are in-yer-face songs in minors and sad songs in majors but the rule of thumb is a good one).

Next stop should be sevenths. Sevenths are emphatic, they are like majors but with edge, more sportscar than family saloon. Sevenths are very jazz (minor sevenths even more so). The G to G7 transition is well worth getting as it's used in so many songs to perk up a verse that ends on G. The D > D7 change a common emphasis too but harder to switch as a beginner.