Places on the Internet we like to Go, and think you should know about:

Pedal Building Supplies

Smallbear Electronics - Great place to get just about everything you need

Pedal Parts Plus - Enclosures and more

Tayda - Cheap parts from Asia

Dr Tweak - Smallbear on a small scale for Brits

JMK Guitar Services - Guitar and Bass repairs and Electronic Upgrades

Pedal Building Forums

Madbean - My Favourite place to go for DIY pedal community

DIY Stompboxes - One of the oldest and most popular Forums for DIY pedals

Free Stomp Boxes - Great resource for schematics and Boutique info

BYOC - Especially helpful if you want to build projects from BYOC