VHDL Style Checker / Check Style
It would be better if you use already installed software text editors for checking your syntax errors. There itself you can correct your typing errors or syntax related issues, data type matchings, signal/variable namings etc. Coz it also provides proper text coloring/highlighting of conditional statements, loops, hierarchy etc. Language templates documentation is also given inside the software application for help. 

You can also install latest notepad++ for that matter from here for re-editing your source code files (It can be used for almost any coding language, not just VHDL). Sometimes it's easier to go through codes in the notepad++ editor rather than opening it in the heavy software application and also better than a simple text editor.

And concerned to your style guidelines, I think it will automatically come to you as your learnings about VHDL grows.