Learn from Your Favorite's Songs

This is one of many ways to learn guitar. If you already knows about chords, scales, technique, warm-up exercise, etc. Now it's the time to play your favorite's songs. Why? To give you an influence, to practice solo, to train your ears, to practice chord progression & chord movement, strumming, picking, your guitar technique, etc. After you practice your technique or speed picking, you might get bored. Why don't just pick a song for learning.

Choose the song based on your skill level. If you just learn guitar, choose the song that is easy to play. Once you've succeed increased your skill, try to play the harder songs.

Find the tune by your ears

How need to fine the tune first before you can play any song on your guitar. You can use your ears. Make sure your guitar is in-tune. Try to find the chord progression first. Divide the song part by part. Start with the intro and then the verse. Continue to the chorus, bridge, etc.

I know it is hard at first, you have no idea where to start. Play the song on your stereo, pc or ipod. Repeat it until you familiar with the song and then try to find the chord proggresion of the song. After that, try to find the guitar fill, variations, and the solo (if any).

There's a lot great articles about ear training. I recommend you to read one of these articles.
Ear Training @ Cyberfret
Ear Training @ GuitarNoise
Ear Training Exercise @ Wholenote
Ear Trainer Online (quicktime plugins required)

Solve the song using tabs

Another way to solve the song is using guitar tabs. But you have to know how to read the tabs. There's a lot of guitar scattered around the internet. Just 'Google' it. But still, even you can use the tabs, it doesn't mean that you don't have to train your ear. You still have to train your ear. It will give the sense of musicality. Btw, you can find how to read the tabs here.

There's a great guitar tabs sofware. It's Guitar Pro. It's not just act as tablature editor but it have audio playback, midi/ascii export import, guitar fretboard, scales tools, digital tuner, speed trainer, metronome, etc. Also you can use it for drum tabs or bass tabs and any other instruments. You can try it here.

There's also another software for guitar tabs. It is Power Tab. Power Tab is good guitar tabs software too. It doesn't have feature as much as Guitar Pro. But it still a good software. You can download it from here.

For Guitar Pro and Power Tab files, you can find it at ultimate-guitar.com or just 'google' it.

P.S : You can import Power Tab Files into Guitar Pro