The following tasks will walk you through compiling your own firmware, kernel and userspace environment (i.e.: bash, binutils, etc.), followed by getting it up and running on the board.

Suggestion #1: After manually solving each task, automate the steps you've taken by writing a Makefile. Chances are that you're going to have to rebuild things (at least partially) dozens of times.

Suggestion #2: Since you won't be working alone, run a git init and add dependent repositories as submodules so that your partner's on the same page. Don't forget to add --depth 1 to the git submodule add in order to reduce the cloning tine and size of your subrepos.