Well - it sounds as though you have wireless on the iMac, and just need a wireless router.
Not sure how you currently access the internet - but note that the
Airport Extreme base station is a router only - and requires an ethernet connection to a DSL or cable modem for internet access.
Hopefully the Airport router will come with comprehensive instructions...
If you have a question you can click on 'Support' in the menu bar at the top of these pages and enter the question in the search box at top left. If the topics offered are, let's say, semi-relevant, then subtle variations to the wording of the search term can produce more helpful results.
Presumably the Windows box has wireless built-in, also? If not, it probably has a wired ethernet port that can be used instead.
A simple overview of simple networking (with links to other info, most of which work) is here
http://docs.info.apple.com/article.html?artnum=106658
Assuming that you wish to use wireless access for internet browsing from the iPod Touch - using the faster USB connection to iTunes on the iMac, and charging - I have seen an instruction-manual-resistant Touch owner connect via a (non-Apple) wireless router almost instantly - so that may not be a problem. And there's always the manual...
Wii wireless support is here
http://www.nintendo.com/consumer/systems/wii/en_na/online.jsp
and, no doubt, in the manual...
Windows networking links are here (also linked-to in post above)
http://discussions.apple.com/thread.jspa?messageID=6936836�
Once you have the wireless router up and running, connecting to it may be easier than it sounds. If you do have a problem, the more specific details you can give, the more likely it is that someone will be able to suggest a solution.
Good Luck.
