I was wondering if there are any good sites (or books) that could give me information on altered tunings, for example the different chord shapes in open tunings or with capos, I am playing more acoustic stuff and I would like to experiment a bit more than the simple open/barre chords Im using at the moment
try a cut capo. it only holds down the A D and G strings. sorta like sus4 open. its pretty fun to play around with, plus if you have an old kyser-type capo, you can make it yourself. ive sorta looked for some lessons and stuff but i didnt find any, but i wasn't looking that hard.

i think its called a foote capo also.
Thanks for that, but I am looking more into how to play things (scales, chords etc) in different tunings as opposed how to tune to them
^Figure them out yourself - do all the hard work yourself, it pays off and it's a lot more rewarding.

Take a tuning, a scale and chord - and try plotting them out the fretboard yourself. Learn the notes & intervals and move them around according to what tuning you're using and how the notes have changed.

There's no point just reading about it - you have to do it, and with a deeper understanding of why they've moved you're, in turn getting a deeper understanding which can lead you to other places, instead of staying stagnant by just knowing a chord shape or scale pattern.