Be aware that OpenOffice still has some trouble with certain bits of formatting: specifically TABLES. Otherwise its a brilliant piece of software. I'd recommend disabling the auto-load on startup though. It tends to take longer in total if its trying to boot up the same time as your virus scanner, IM software and everything else. OpenOffice is also great because it can save anything in PDF. If you still have Office 03 (the superior Office suite I feel), its almost worth keeping OpenOffice on one machine you use if just for this feature.
OK, so OpenOffice is great buuuuuut, if you like it, heres some really good news. Its merely one of a tonne of high quality free software packages. Bit of backgound: most of these packages are a result of the GNU free-software movement. Basically, a bunch of rich or kindly IT people, mostly in the US, have this goal of making software free and open. Not all packages are as open as others, but there are free high-quality equivalents to most of your favourite programs. Some are even arguably better than the program they mimic (looking at you GIMP and Audacity).
Heres my top 3:
* OpenOffice.org
* GIMP (Raster graphics ala Photoshop or PS Elements)
* Audacity (Audio editing, lets you slow down pop songs! I'm quite willing to make a tutorial for this if anyone asks as its an amazingly useful trick)
Other freebies I use:
Inkscape (vector graphics ala CorelDRAW)
Ubuntu Linux (Free equivalent of Windows, no really! Good for turning an old low-end computer into a slideshow and music box)
Avast (virus scanner, not GNU but they only charge money for the Business version and the Home version is comprehensive.)