Just adding info to the page is good. I've not gotten complete hang of using the infobox myself. I usually just copy/paste something from a similar item/skill/whatever and then change the appropriate information. Note that some information that is filled in by the server, or relational to information filled out on another page, may take some time to update properly, up to 24 hours if I understand right. It might be why you didn't see the information show up. There's a "refresh" tab at the top. I hit that and now it shows. I can't recall if these will process through automatically or if they have to be forced to update.
There are some pages flagged as legacy that need to be moved to the appropriate legacy page. Name the new page "Legacy:<page name>." Be sure to remove the {{OutdatedPage}} tag after it has been moved (as it is now on an appropriately named page indicating it is legay). Be sure to leave information that this is legacy. You can then go back to the redirect page, edit the page to delete the redirect, and put the new, current information in. Save old information if it is relevant, of course. I've been leaving notes for players looking for the proper page (they get the legacy page instead of the current or vice versa) so it's easy to click to the right page.
Some of the pages need details of data updated. Make sure any values used are from a quality 10 item. (The multiplier for stats is figured as the square root of Q/10. Divide the stats by the multiplier and you should have the base.) They may also need instructions or written details updated properly.
I'm not an admin, so I might be missing some things. I tend to update things as I run across them in the game. Right now that isn't often as I've only been playing around a bit here and there. We do have a thread for general discussion of the wiki or specific questions stickied in this forum:
viewtopic.php?f=42&t=42391. Feel free to read through it for anything that is being asked for.
A lot of new items are missing icons or pictures. Icons can be grabbed directly from the game server and uploaded. (I forget URLs to do this off the top of my head.)
Opinions expressed in this statement are the authors alone and in no way reflect on the game development values of the actual developers.