Read some build alongs, there are a few in the how to section of this forum. Also use your favorite search engine to search for other how to build a bow type posts. You will find many resources that will help with your quest. Good luck on the build.
I would say start with a longer bow 68-70" nock to nock. Grain is very important in board bows so even though your board is knot free you may want to back it with another material i.e. silk, rawhide, fiberglass, thin hickory etc.
TBB or traditional bowyers bible 1 recommends using a design 1 3/4 wide for maple, I would use 2" wide for a safety margin since it's your first try.
Read, read, read some more then dive in, you'll learn more by doing than anything else.