Welcome to CR! First things first, questions about the site belong on meta - every Stack Exchange site has a meta counterpart. So I've migrated your question over here.
Feel free to browse some of the site's top-voted questions - you'll find they mostly share a number of common points:
- they provide sufficient plain-English context so that reviewers can know what the code is doing without having to figure it out from the code itself.
- they have an interesting title that hints at what the code is doing (not at what OP wants out of a review).
- they all include the code to be reviewed. All of it, and with sufficient contextual code so reviewers don't need to make assumptions or guesses about such function or such variable.
As long as your post doesn't exceed the 30K characters limit imposed by the Stack Exchange system, you're good to go.
See How to get the best value out of Code Review - Asking Questions (and/or browse the faq tag on this meta site) for more information.