A good source for open office help can be found at this blog.
Major benefits of using Open Office
platform independent
compressed file size
similar interface as other office suites
handles other documents types
free
Writer
Procedure for opening and saving Microsoft Office documents with Open Office
Tools->Options...
Load/Save->General
Default file format
Autorecovery and format warnings
Calc
Printing column headers on multiple pages
Format->Print Ranges->Edit...
Rows to repeat = $1
Setting up page layout (Grid, Formulas, Scaling)
Format->Page...
Sheet
Presentation (Impress)
The initial install of OpenOffice does not come with many templates such as backgrounds for presentations. Here are a couple of sites where they can be downloaded: