One of my questions were put on hold and I was told to edit it so that it fits the website, so I did edit it. Now how do I submit it for review?
This happens automatically, but only for the first edit. Namely, if the question was edited and the reviewers felt that it should be left closed then even after future edits it won't get sent automatically to the review queue.
To overcome this problem, you can also post a request on Requests for Reopen & Undeletion Votes, etc. (volume 01/2015 - ) [current version] explaining why you think that your question should be reopened.