Bestpianolessons.com

This site focuses on beginner lessons. They are pretty well laid out and also include midi files.

Visit site: http://www.bestpianolessons.com/

Levels: Beginner

Hearandplay.com

This site requires that you sign up and give your email address, make a login password etc. before you can get access to the resources. Once you sign up, you get taken to a members section which gives you access to the site’s lessons. You can also create your own profile on the site and upload photos of yourself if you really want to.

Once you get in though there are a lot of free, informative lessons so I recommend signing up.

You can also access files which have been uploaded by members themselves.

Visit site: http://www.hearandplay.com

Levels: Beginner, Intermediate, Advanced

Musicandyou.com

This site has free and paid lessons on offer. The free lessons are pretty good and include a detailed PDF of the lessons and audio. They focus mainly on blues and jazz piano.

Visit site: http://www.musicandyou.com/pianolessons

Levels: Beginner, Intermediate

Learnpianoonline.com

The free lessons are quite good and go through most of the basics and then move on to slightly more complex topics. There are audio files as well which makes it a lot easier to follow.

Visit site: http://www.learnpianoonline.com

Levels: Basic, Intermediate

Guitarweek.com

This is a useful site for learning chords and scales. The site mostly uses colour PDF diagrams in the various lessons on offer.

Visit Site: http://www.guitarweek.com/

Levels: Beginner, Intermediate

Other Resources:
1. Piano lessons

Gopiano.com

This site has a handful of lessons, including real player files. Aesthetically not the nicest looking site but it has some useful tips.

Visit Site: http://www.gopiano.com/

Levels: Beginner