If you are interested in learning to type documents using TeX or LaTeX (which I encourage you to consider), here are some resources.
If you use a mac, then you can obtain all of what you need at MacTeX. It should be noted that the main download is a gargantuan 1.6 Gb download, though smaller ones are available. This comes with a few choices of editors; the one that I use is TeXShop.
It should be noted that there is a bit of a learning curve for using TeX; there is no WYSIWYG editor, and you will have to get used to compiling your files. For the most part, this isn't particularly difficult, though occasional compile errors will result for a painful search for unmatched brackets or mistyped words. If you've done any computer programming, however, you will likely find this to be no problem.
This also has the advantage that it outputs directly as .pdf files which can easily be viewed anywhere, instead of as .doc files (or open office files) which require a word processor to view. They also look prettier, and math formulae are easy to type!
I encourage you to consider trying to use TeX. Once you get used to it, you may find that you never go back to using word/open office ever again.
Lastly, if you want more information about anything TeX related, there is a website called TeX Stack exchange on which you can ask questions. Good luck!