Hi Ninnie,
This BOM, like many you purchase from quilt shops comes with fabric that has already been selected and cut (with some extra, bless their hearts), into strips. You follow the directions to cut out the pieces from each fabric provided. There is generally a set fee for the quilt kit that is spread out evenly over the 12 month period. Some BOM's are only 6 or 8 months.
There are some shops tho, that "kit" their BOM's putting together their choice of fabrics, not necessarily those the original pattern used. As well, there are other BOM's that you get the pattern and use the fabrics of your choice. A good example of that would be the Moda University classes given at many shops, brick and mortar as well as some online shops. I am also involved in a Moda U BOM at my local quilt shop.
There are also FREE BOM's usually found at online through quilt shops, individuals and groups. They supply the pattern each month, you use your own choice of fabrics for those, too. Silly me, I am also involved in a couple of them. LOL
BOM's can be quite addicting, as many of us feel hey, we can do a block a month, right? Well, what happens when you get yourself involved in a few or more of those? Eventually, it's time to put them all together. Then, the real work begins! Hope this helps.
Happy quilting,
Karla