How Would I Improve On My Grammar?

My first suggestion is that if you are able to read English, do it!  Read all sort of newspapers, books, journals, magazines - anything you can get your hands on.  The more you observe good grammar in use, the better your own will become...  

A note of warning, if you want to learn "proper" grammar, avoid sites that are not vetted, (ie. No editing process, like a book, magazine, or newspaper should have).  The grammar may not be standardized throughout a non-vetted source.