Upgrading Wired Network

Hello,
I am currently upgrading a wired network.
I have completed 75% of the upgrade.
Now, my client wants to add wireless fuctionality to the existing network upgrade. I’d like some suggestions on, “best” practices for intergrating a wireless enviroment, to a wire network.

My platforms are Windows XP on the front-office, & Linux (Red Hat) on the backoffice…

Thank you,