Music Theory by Dummies:
This is the C major scale, The notes are in bold, the distances between the notes are in parentheses:
C(1)D(1)E(0.5)F(1)G(1)A(1)B(0.5)C
Pick a note, let's say 'C'. This is going to be the 1st note, aka "root".
Count to three upwards, you get 'E'. This "third" note determines if your chord is major or minor - if the distance between it and the first is a two steps then the chord is major, if it's one step and a half then it's minor.
Now, move on ahead to the 5th note from the root, 'G' in this instance and voila! A C major chord.
If we were to try this with 'A' for root, we'll get 'A' 'C' and 'E' which will be a minor chord because of the different distances between the root and the third.
And that's it, basically. On top of that, you'll get variations like 7ths, 9ths, 4ths, 13ths (pretty obvious, I think) and all that other crap, but for the most part it's all just major and minor, or even just power chords (just the 1st and 5th notes, making them 'neutral')
Anyway, using the aforementioned system, find all 7 chords in the scale, then play them in whatever order you like - they'll go well together. Then build a scale out of some other note, and repeat the process. It really helps out to just write out the scales for all 12 notes (shaprs included) and the chords for them on paper - helps build hand stamina too!
Almost forgot - in that scale I showed you, you'll get a chord from 'B', 'D' and 'F' which will sound neither major nor minor - it's diminished (half diminished technically, but no one cares) and unless you're keen on making classical or jazz compositions right away, I recommend that you stay away from it for a while.
I really shouldn't be allowed to teach people. Look around the article section on the site, there should be something there about chords. Good luck!
(edit: a bunch of things)