What type and what size file are you trying to upload?
The current month's entries can be found in the gallery labeled "Current HOTM Entries". However, because of our minimum participation requirement, I don't start approving new entries until sometime after the middle of the month, to give folks a better chance at having met that minimum post requirement. And most pictures don't get entered until the last couple days of the month, so the galleries would look very sparse right now anyhow.
The polls for the contest don't open until the first day of the following month, at which time I create a thread for each of the three contests that include ALL the approved entries to look over and then vote for your favorite. That poll stays open for a week and is closed on the seventh day...winners announced that day or the next.
Contest Rules and Submission Links
What is this month's Photo of the Month Theme?
Hope that helped some!