i only have one spot in my yard that gets enough sun for a garden- and the soil sucks. lots of gravel and the dirt is poor at best. i know i could dig it out and bring in a truckload of topsoil, but i'm curious about this other idea i had. i am a cabinet maker and have access to more sawdust than any garden could possibly need. i know fallen leaves tilled into the soil are good for gardens. whats the difference. right? not a quick fix, but if i do it regularly will things improve? any species i need to avoid?

Yes, use it as is and supplement the nitrogen if necessary or use it in the compost pile. One other wood not to use besides treated and plywood etc. is walnut. Walnut contains jugalone a chemical that inhibits plant growth, natures Round-up. RScott