Do I have to wait until the Student Sprint to work on changes?

Nope! You can start whenever you want, and we'll help! At a minimum, you need your development environment set up by the Sprint, but there's no reason not to dive in and start early if you want to. Many students have.

What editor should I be using?

We don't mandate that you use any particular editor. Your mentors use a variety of editors: Vim, SublimeText, PyCharm, and probably others. Use whatever is productive for you.

What is a Local Site?

One of the services we (Beanbag, makers of Review Board) offers is RBCommons, a Review Board hosting service where people can get an instance for a monthly fee, instead of maintaining their own server.

Under the hood, RBCommons is a single instance of Review Board, divided up into multiple sites through a mechanism called Local Sites. Each one gets its own namespace under the domain (/s/my-site-name/), and each gets its own dashboard, review requests, users, etc.

Here's a couple examples of public Local Sites:

Local Sites are used less often for standard Review Board setups, but are still very important to keep in mind when developing. Particularly when writing queries against things like review requests or users. You'll usually see a local_site field on models that work with these.