Tech Shop is great, but there is a lot of info to track, and a binder of lots of info is unmanageable
Metal:
OnlineMetals.Com - Thyssen Krupp's distro 
Metal Super Market

Plastic:
-Sabic - San Jose plastics vendor
2250 Zanker Road, Suite B SJ CA 95131120  Tel: 408-432-3800 $44acrylic from sabic $39 petg from sabic
-Tap Plastics (expensive but everywhere)

Metal+Plastic+Tools:
-McMaster - Expensive, but fast
-Use-Enco - metals, plastics etc
-valley tool and supply

Wood:
Baltic Birch
-Aura Hardwoods- -210 Phelan Avenue SJ - 408.275.1990 - 1/4 5x5 - 23.39 50 sheets
-MacBrea - 2211 Ringwood Ave SJ - (408) 526-9663 Finland birch - 1/4 - 47.78  4x8 or 8x4 (normally has baltic, but out, finland is closest)
-Southern Lumber -  1402 monterey highway - (408) 297-WOOD (9663) 4x8 - $75 


Do not buy!
US Plastics - religious f's