First of all, before you upload a map, look at your map and compare it to a map that has been rated 3/5. This should be the least rating that your map should get. Is the quality of your map equal to or greater than the quality of the map you are comparing your map to?
Second, if you're set in the direction of uploading your map, read the Map Submission Rules:
http://www.hiveworkshop.com/forums/rules-information-710/map-submission-rules-228244/
Make sure you follow all of the rules.
To upload your map, just go to the Map section and press the Upload button (above and to the right of the maps). Make an appealing description with BBCodes or a template. Check out other people's map descriptions to have an idea. (Make sure you're looking at approved maps.)
Finally, there is no reason to rush uploading a map. Read tutorials, ask questions, and improve all the features that you can improve on. If you want feedback on your map but it isn't finished or it isn't up to the standards of this site, post in Map Development.