Paint a base coat. *ignore my wonky nail. It chipped weird.
Paint whatever base color you want. I did a matte black, and silver for an accent.
To do the webs you need a striper polish, (I got the black at I think a shoe store for around $2) or a nail art brush.
You paint three lines.
And then little curved lines in between them.
I don't know how to describe how to do it, and my video thing isn't working. Have a doodle. Also cutepolish on YouTube did a Halloween nail art video- and she did spiderwebs.
When you're done clean up around your cuticles if you need to with a q-tip or small brush dipped in polish remover. Then topcoat. And you're done.
Hope your nails turn out well! Tell me what kind of guides you'd want and I'll work on it.