ExtremeCoderz multi poster is fairly difficult to start with but once you get used to it you should enjoy it, some people have found it too frustrating and left it altogether in search of a better multi poster.
A lot of them will be fairly difficult to use unless you give it the time and patience. If you truly want to upload files more than once a week you should consider getting a multi poster application.
You can find free ones such as dcrews multi poster or you can get the paid for multi posters such as themaposter, warezme's multi poster or multi poster 5.
Multi Poster 5 is the fifth multi poster created by Jayfella. I'm pretty sure he was one of the first to start creating an application capable of doing this although I'm unsure if warezme's poster was before or after.
dcrews = free
multi poster 5 = 20$
themaposter = 25$
warezme's AutoPost Maker = 6$ for 6 months or 11$ a year (unsure if its still the same price)
These are the prices I know of/found.