My rec here would be Notetab Pro. It's a text editor, not WYSIWYG, but perfect for creating text files for the boards, and has a lot of useful features for creating web pages etc. There's a free version that doesn't have a spell checker, you can upgrade to the version with the checker for $19.95, or a deluxe multilingual version for $29.95
One of the features I use a lot is that you can have a load of documents open simultaneously - for example, each of the chapters of a book as a separate file - and do global or all-documents search and replace.
If what you want is an all-singing all-dancing program equivalent to Word, however, your best bet is probably the Openoffice suite, which is free and very good.
http://www.openoffice.org
