There are a lot, suggest me one good u've tried. Pros and contras, etc.
Musicmasterpro
jamorama
vguitarcourses
etc.
As far as I'm concerned there's nothing as good as a private teacher, but I know that it's impossible for some to go for weekly lessons, and for others it's not affordable. Some On line lessons look good, I've checked a few of them out and there are as good as you can get without having a private teacher, some have as many as 10 – 20 free lessons to see what you think of them, here are a few, check them out and you be the judge :
http://www.jamplay.com/
http://www.billbrutal.com/
http://www.guitarchordsmagic.com/
http://www.8notes.com/ (Click on the guitar)
http://www.guitarforbeginners.com/
http://www.cyberfret.com/
http://www.worldguitar.com/
http://www.fretplay.com/
http://www.ultimate-guitar.com/
http://www.chordfind.com/
http://www.wiki.com/ (rapidly learn acoustic guitar)
http://www.stringdancer.com/
http://www.learnplayguitar.net/
http://www.guitartutoronline.com/
http://www.playingnotes.yablog.com/
http://www.absoultelyunderstandguitarplaychord.net/
http://www.top100guitarsites.com/
http://www.chordie.com/
http://www.get-tuned.com/old-guitar-tuneechords.com/
Something above should help you to get started. Some of these sites want you to buy their Cd's, DVDs, videos, and some have the live tutors….I play and teach classical and acoustic guitar so I haven't taken these courses but I've checked them out, and if I was just starting guitar I would certainly appreciate these sites !!!!!!! Good luck with these, I hope something works for you, bye !!!!!!!