Thiis isn't really an answer, but have a look at the human models, (the
male and female ones) to see an example of how layouts are used. I
didn't create the model, but I posted a forum note describing how to
use the layout file in controlling the model assembly position.
I run 2001, so don't know if there is additional functionality in layout
for wildfire, but I find the most useful aspect to be a central repository
for relations and global datums. I don't find the sketching aspect very
useful. If you have an assembly with many parts and subassemblies,
controlling them with relations at the assembly level only can get cumbersome.
Using layouts you can create global parameters and datums with the layout
then declare them to the part or subassmebly as needed. Updating the
layout then updates all declared models.
I have run across some tutorials over the years, but nothing so helpful
on this topic as diving in with simple test layouts and building from there.