I seem to remember it being screwed into, or inserted into the bottom front of the case. I went looking for my instructions for a different Antec case (which also had support for a 2.5" SSD) and couldn't find any.
However, I do recommend the adapter bracket mentioned above anyway.
Don't worry about it being a "poor decision"; everyone is different. If you ever decide to get an SSD for Windows you'll discover that you'll want a minimum of 80GB but 120GB is recommended.
I had a 60GB SSD and Windows 7 x64 installed, updated, programs etc and I had 35GB used (fine you say). Well, I don't have games on it but with continued updates, auto System backups etc I had to get a second drive and now I'm at 75GB, so get a 120GB drive from the start.