I'll let Trance share any info about the backend of the TFL archive, but I can tell you it involves a gazillion SQL database entries. I think we have something like 60k or 70k "toyids", a unique number assigned to each part, figure, set, package, etc. all with data describing them.
We at Transformerland-North have sold a couple MMPR collections (through eBay), and were surprised at how poorly documented such a popular series is.
There are two axes of toy archiving: accuracy and completeness. At TFL, we hold the highest standards for both before going public with an archive section. Typically, we aim for 100% accuracy and 80-90% completeness before releasing a series archive.
What I mean by accuracy is that someone who does not know a toyline can look at your page and determine correctly if anything is missing from a set. Catalog pictures won't do- oftentimes a gun is in its holster, a figure stand isn't shown, or something of the like. Sometimes it takes a lot of work to figure out what an uncommon figure actually came with.
Completeness is something a lot of archive really lack: they have great pictures of the the first ten figures in the line, but no information for the later four figures. We ran in to this frequently when researching TNMT. Anyone can tell you what Splinter or Raph came with, but who has accurate identification of the accessories from Road Ready Mutations Splinter? Not many.
If you wanted to start your own MMPR archive, you could do it simply by taking clean, clear pictures of each toy with its accessories, and titling and categorizing it. If your content is good, it's better so sift through lists of pictures than have no info at all. TFL-style archiving requires a lot more steps and backend work. If you feel you can put together a really nice archive for MMPR or even some subseries within the brand, we could talk about cooperating with you on such a project.