Multiple WP DropDown Categories

Hello!

OK so this is my blog

http://www.thewhatwherewhen.org

yes i know, its a big crazy mess…

im trying my hardest to find the best way to navigate the site.

I think it would be dropdowns similar to:
http://www.artrabbit.com/all/events

Where the dropdowns on the left work together, so you can be quite specific to find a post.

I have tried several ways of this… but I can’t seem to get it working.
Problem is, I am no php whizz… as you can see… I can edit things, but not write.

Each dropdown would be the children of one category. I would also like a tags dropdown to work amongst these category dropdowns.

Anyone have any ideas?

Thanks!