Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

For making plans I'm currently using Vectorsoft Draw - a 2-d drawing
program on PocketPC and experimenting with Google Sketch-up for 3-d
drawings. Move away from paper a couple years ago. Would like to hear
comments on what else is good.

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross