The defference of these two words is very simple. 意味 is a noun which means "meaning" and 意味する is a verb which means "to mean". *Sometimes it's used like an adjective. (意味する+noun, for example, それが意味すること / 意味するもの.) I hope this helps you.

I'm linking a webpage to you called Honyaku Star. It's less a dictionary and more of a professional translator's collocation database. It can be very useful to find examples of words and phrases in use. http://honyakustar.com/jp/意味する