I've done a ton of web3d earlier in the decade and not as much now...what are you making the 3D for? Ie, are you wanting to make stuff to use with code you write for a game? or just looking to make cool graphics for ads, web, etc?

I ususally point people to Blender if you're wanting a WYSIWYG tool and it can export to X3D for the Web or other formats that can be used with 3DS Max, Maya, etc and is the right price (free) vice the $5K for a legal copy of 3DS Max, etc. Course if you're the type who codes your HTML in a text pad, then X3D-Edit is a cool, free tool for X3D (web based XML 3d). Believe 3DS Max and Maya can only export to X3D now-adays but haven't mucked with those tools for a while now.

Blender and X3D both have some decent, free tutorials online. I usually teach folks to:
1 - Make something with geometry
2 - Add color and light
3 - Add some textures (2D images mapped to 3D)
4 - Make it move (ie animation)
5 - Repeat, then make a basic game to get down game scripting
Happy to help, just email or pm.