Consider the (Re)sources
When checking Library or book store resources on writing , be sure to look at the publishing dates of the books first to see if a relevant resource or not. There have been so many changes in the last decade that the best bet for current information is probably the Net.
If intent on submitting to a particular Review or Magazine, do a review yourself of their back issues and make sure your subject corresponds to their output, and if you have any questions, send an e-inquiry first and save everybody a ton of time and trouble if your material isn't suitable for their theme /mandate.
Query letters have remained basically the same , although one pagers are more appreciated than the verbose synopsis accepted in the past --- there's the old addage that you have 10 seconds to capture anyone 's attention so, your first and second paragraph on the Query better be the best work you've ever done :) It can be a bit confusing if a publisher asks for a Cover letter because sometimes they want a combo of the writers contacts , brief bio and a synopsis all in one. If in doubt and semantics are an issue, do everything in the Cover letter and let them figure it out and ask for the 'separation'.
Fortunately most contest submittables these days are by e-mail and often through Submittable, a vehicle many publishers use for applications/submissions. You'll be given an account which you can use for future reference with other submissions. Avoid those contests which require paper copies---unnecessary copy and mailing expense-- like the Canadian Hanged Arthur awards. What, they can't share an e-mailed attachment ? I think it's a case of : 'But we've always done it this way...'
Checking sources and resources out thoroughly is work but keep in mind : measure twice cut once, a stich in time says nine etc.... :)