Hiya Squizzlybear,
I'm also teaching myself to play. To learn which fingers to use for chords i use www.chordbook.com This is a great site for learning chords, scales and even tuning your guitar if you haven't a tuner. It has numbers on the chord diagrams showing where to put your fingers ie 1=first finger 2 =second finger etc, check it out, i found it invaluable. After a while and with lots of practice you wont think about making a chord shape, if will become second nature.
X on the chord chart means not to strum that string, and o means strum the string.
When you see a chord diagram which has a number on the left of it, this denotes which Fret to start your chord shape. Chordbook .com is actually quite easy because it has a great diagram of a guitar neck showing you exactly where to start your chord shape.
And i'm guessing "the text only music sheets" that your enquireing about are the "tabs" short for tablature, this is what guitarists use to learn solos as well as chords and is very easy to understand once you get the hang of it. I dont use them at the moment because i'm happy playing chords on my acoustic, and just improvising on my electric, so i'll leave that for someone more qualified to explain to you, but believe me its dead easy.
But it depends what you want to do, if you want to learn solos then maybe learn a scale or two and get into tabs. If your like me and want to learn songs to acompany your self singing, then learn a couple of easy songs playing chords.
I hope this helps. Bare in mind i've only been playing for less then a year myself, and i'm sure someone out there in Chordie land will be able to add to what i've said, or even correct any duff advice i've given you.
I've learned loads form here and i'm glad to be able to give s litle back.
Peace...Andy