Where Does a New Person Find Information About Open Source Software
So, you've heard something about open source, and now you want to know if it's going to work for you. You might be surprised at the answer, perhaps disappointed, or maybe some combination of the two. It's actually not all that different than how things work in the world of proprietary software when you sit down and think about it. How many people do you know who wanted to do X, found some software that promised to do it, then found out that the software doesn't quite do X the way you were hoping. Sometimes you even get to pay lots of money to find that out!
Where to Get Open Source Software
Open source software with any kind of following will usually have a page on Sourceforge/. This doesn't mean that there's a functioning application necessarily; the people who have a project going might still be in just the planning stages. The app, if there is one, might be pretty old and is no longer worked on either. I've actually got an app up there (openinvoice) which is an invoicing app written all in bash. I've since created a php (much prettier I must say) version and haven't gotten around to uploading it yet.
There is a plethora of gems on Sourceforge though. All sorts of fully functional free software with active developer and user bases is there for the taking. And if it works for you, you can help others discover and use it by contributing back to the project somehow; this can mean with money, as a tester, creating user documentation, or whatever toots your horn.
Another site I like to visit when I'm hunting is Freshmeat. You'll find a lot of the same apps on Sourceforge, but there are quite a few on one site that aren't on the other.
Application Specific Information About Open Source Software
I love pointing folks at this site: http://www.osalt.com/ OsAlt is awesome. You go a hunting for a proprietary app, and you get a list of open source alternatives to that app. Searching for Outlook, for example, shows me three apps; Seamonkey, Thunderbird, and Evolution are all three viable alternatives to Outlook. I've never tried it, but I hear that Evolution will even hook up to an Exchange server…
Another place you can look is right here on this site. Feel free to ask questions in the comments or via the contact form. I'm more than willing to answer visitors questions. I'm not selling you software, so you may find that you get an honest answer.