Here is a short video on just a few things to know on how to manage grazing. This would be a 100,000 foot view of things, just the bare basics.
As you can see, managing grazing is a science unto itself. Properly and successfully finishing cows on grass rather than finishing on corn is like having a masters in grazing.
Finishing without seeding annuals, like we do, is really just masochistic but what fun would life be if everything was easy.