Hacking of Sega games belongs in this forum; hacks of Sega games either belong in E&RE or TD.
The Sega Retro IRC Channel is irc.badnik.net #sega. You can use the Mibbit or CGI:IRC links at the top of the page to access IRC chat if you do not have a client.
We don't have your Sonic Retro accounts migrated yet, so just register an account with identical username on http://www.segaretro.org/ and get editing.
When creating an article for a game, take a look at how other articles are written to get a sense of how to write your new one. This will keep everything up to a certain level of quality.
Manuals are to be uploaded in cbr format. cbr, short for Comic Book RAR, is just a rar file with the extension .cbr. The files in a cbr file are formatted pageXX.ext, where XX is padded with 0s. So, for a 30-page manual, you go page01.jpg, page02.jpg, ... page30.jpg; for a 300-page manual (gasp!) it's page001.jpg, ... page010.jpg, ... page300.jpg. We are doing this to save bandwidth on the server, so get out your Comic Book Readers and get ready to learn!
Files should be named consistently. Use the format gamename_console_region_mediatype.ext or similar. For example, the US Genesis Dynamite Headdy cover should be named DynamiteHeaddy_md_us_cover.jpg, DynamiteHeaddy_MDUSCover.jpg, etc.