The procedure will be slightly different depending on if you want to create a Fusion drive or not. I didn't want to do that. I took my old laptop to the store when I picked up the new Mini and had them transfer everything over and download updates, etc. The Apple store has much faster internet than I do at home. Then I backed up the machine, installed the SSD, and then installed Mavericks on the SSD over the interwebs. I left the spinner in the machine because it was a pain to access things. Once the SSD was up and running and updated, I used the migration utility to move all my information from the old spinner drive to the SSD. Then I formatted the spinner and set it up for data. Moved all the big libraries, pictures, movies, etc. over to there but left all the apps on the SSD as well as some of the data - things I use a lot. It worked out well.
I chose not to create a Fusion drive because, although I do back up regularly, the chance of both drives failing at once is slim. If just the data drive fails, I can hook up the backup drive and be good until I replace it. If just the SSD fails, I can boot off an external drive and be good until I can replace it. I keep old drives around for emergencies so YMMV. In a Fusion drive setup, if either of the drives fails I believe you have to replace and restore, so no way to limp along in the meantime.
OWC does have very good videos, just follow their instructions and make sure you get the right kit depending on if your original drive is in the upper or lower bay.