Are you all set on how to do the WLAN bit?
If it helps, the TiVo (at least the standalone one that I bought - I don't know about the ones that are integrated with DirecTV boxes and so forth) come with version 3.x of the TiVo software, that supports connections via phone or wired Ethernet,
not wireless/WLAN. So you first go all the way through the TiVo setup process using a regular phone line, and in the process theTiVo downloads and installs v4.0 of the software, which
does support WLAN. Then you plug the WLAN adapter into the TiVo's USB port, enter the necessary WLAN information, change the connection from phone to wireless, and do a test connection to make sure it works. Went without a hitch for me.
Also, TiVo's website recommends the Linksys WUSB WLAN adapter but only the old version (Linksys v2.6) works. The current Linksys v2.8 and v3.0 that are in the stores do
not work with the existing TiVo software (not even TiVo v4.0). TiVo has "beta" software that does work with the current Linksys v2.8 and v3.0 adapters, but you have to specially request it and then wait for a reply. Quite a misstep by TiVo, I think!
Anyway I went to Best Buy and bought a Microsoft "510" USB wireless adapter - it is also listed on TiVo's compatibility page, works perfectly with both my TiVo and my existing Linksys "b" WLAN, is nice and small, comes with a long enough USB cable (about 4'), and cost about $50.
I know anyone can get this info from
http://www.tivocommunity.com but maybe this will save you some time.