here's a couple of links.
tatu if you've not already heard of him is a well respected rope Master and definately worth taking a look at.... http://www.ds-arts.com/siteindex.html

the guy who runs this site is an excellent rigger and a great teacher, i wouldnt recommend him if he wasnt.
check it out he has some great links too.

http://www.touwtjes.tk/links_e.html#tutorials

you could try looking up midori, the two knotty boys and esinem too

the best tutorials etc are by randai mai, however it is pretty costly but if you're serious well worth the money.

there are many courses out there, but be careful, look around and do plenty of research before you decide on one.