Wall of drunken text!!
Get an electric tuner.
There's no better way to destroy your motivation, than not being able to tune your guitar. So get a tuner, tune the guitar with it, get accustomed to what the guitar is supposed to sound like, and then start tuning by ear. If you can't get it right by ear, use the tuner. There's a few easy tricks to tuning by ear, but I won't go into too much detail.
Learn the easy chords. A, Am, C, D, Dm, E, Em, G.
http://www.all-guitar-chords.com/ You can check all chords and scales in here. The site is also good for checking up unknown chords you come across while learning new songs.
Once you get the easy chords down, and can easily shift between them, you should move on to barre chords. Barre chords are chords where you use your index finger to cover multiple strings. They will be hard at first, and you'll get a shitload of fret buzz, but keep at it. It'll take you a good few months to make each string ring properly, but don't worry.
If you can, record what you play.
Remember that dude in music class, who couldn't play drums for shit, but always insisted on playing the drums? Everyone hated his guts because he kept banging on those fucking cans, thinking he's John Bonham. He doesn't realize he sucks, because he loses all perspective on his own playing, while he's playing. You'll want to record yourself, because it's extremely easy to get completely lost in your own music. Record your own music, and play it back to yourself. It'll probably sound way different than it did when you played it.
When starting out, play stuff you like.
The best way to keep your motivation up, and keep the hobby interesting, is to play music you actually enjoy.
Go to http://www.ultimate-guitar.com , find tabs or chords to the songs you want to play, and play them. You don't need to play a whole song, just play parts that you think you're capable of playing, and play them. Riffs are your friend. Don't bother trying to play solos while you're starting out. Focus on keeping time, and making the strings ring properly.
Tabs.
Tabs are a simplified version for sheet music, for guitars and bass. Tabs are easier to understand than sheet music, but they only work for guitar/bass guitar, and the notation does not include timing. In other words, you'll need to hear the song before you can play it with tabs.
Here's an example:
E-----------------------------------------5---8----5| Thinnest string
B---------------------------------5---8------------5|
G-------------------------5---7--------------------5|
D-----------------5---7----------------------------7|
A---------5---7------------------------------------7|
E-5---8--------------------------------------------5| Fattest string
Each line represents a string. Lowest E is the thickest string, highest E is the thinnest string. Numbers are the frets you're supposed to press in each string. The above tab is just climbing up the minor pentatonic scale in A [http://www.all-guitar-chords.com/guitar_scales.php?qqq=5&scch=A&scchnam=Pentatonic+Minor&get2=Get&t=0&choice=1] and an example of a barre chord, Am (A minor) [http://www.all-guitar-chords.com/index.php?ch=A&mm=m&v=1].
Tabs and Guitar Pro.
Acquire a piece of software called Guitar Pro [http://www.guitar-pro.com/en/index.php]. Current version is 6, but most songs on the internet can be listened with Guitar Pro 3 and higher.
Guitar Pro plays the tabs back for you, removing the above-mentioned problem of tabs not having timing. GP has shitloads of extremely useful features that I could go on about forever. I can't stress getting this program enough.
For the record, I don't work for Guitar Pro or whoever made it, if this is considered advertising, I'm sorry.
Get a Book.
Get a book about guitar playing and music. I obviously haven't read them all, but the best I've come across is The Guitar Handbook by Ralph Denyer [http://www.amazon.com/Guitar-Handbook-Ralph-Denyer/dp/0679742751]. It gives you insight on famous guitar players, technique, music theory, and on the technical side of amplifiers and guitars, among other things. I found it fairly simple to understand as a beginner, yet deep enough to be of use long after you've understood the basics. The Guitar Handbook has all of it's exercises and examples in tab format, so it's easy to pick up.
I don't work for whoever published or wrote that book either. As a matter of fact, I don't even have a job. Which is why I have the time to write these posts.
Now that I've sobered up a bit, looking at my post, the most important bits are on the bottom. Definitely get a handbook, and definitely get Guitar Pro. The Guitar Handbook will teach you the stuff, and Guitar Pro + internet will give you an endless amount of exercise music to play.
If that wasn't enough, give me a PM. I've probably got a hangover for the whole of tomorrow, and will gladly give advice.