magiic, we need a little more details. What kind of printer and drive are you trying to connect? Can you at least connect to the AEBS with a wireless machine and get to the internet? I mean, is the AEBS working at all? Do you see it in the Airport Utility?
I dont have much experience with configuring the AEBS as an access point instead of a router. So Ill tell you how I set mine up... Mine is set up as my router directly connected to the modem. I then have a external HDD (Drobo) and my Canon connected to a USB hub connected to the AEBS.
This required me to format the external drive as HFS+ in order for it to be recognized by the AEBS. Formatting the drive requires you to plug it directly into a Mac, or if using a PC, a program like MacDrive or MacDisc to format it.
http://www.mediafour.com/products/macdrive/
http://www.macdisk.com/mden.php3
I then unplugged the Drobo from my PC and plugged it into the AEBS. The AEBS saw the drive connected pretty much right away. Click the Disk tab in the Airport Utility and configure sharing by setting a disc access password. Then update the AEBS.
Then, I installed the Airport Utility on all my PCs and restarted them. Once restarted, Airdisk automatically saw the Drobo and asked what I wanted to do. I selected "connect to the drive" and provided the password. The drive mounted as my Z: drive automatically. Contrary to a lot of the articles Ive read, I did not have to map it as a network drive. It appeared in My Computer as Z: without me doing anything but entering my password into the Airdisk popup window. I did this on all my PCs and I now have a shared drive on my network.
http://www.drobospace.com/article/10425/Share-Drobo-on-a-Network--Apple-Airport-Extreme/
This is for the Drobo but should apply to any external drive. As I said though, the last page in this walk through mentions mounting the drive as a network location, but instead, just check your My Computer (If on a PC) to see if the drive appears on its own.
For the printer, this was a little more difficult. I erased all my current printers from the PCs. I then plugged the printer into the AEBS. Then, I had to turn off the printer, then unplug the AEBS, then turn the printer back on and plug back in the AEBS. Somehow, this helped the Airport Utility to see my printer. After doing this, my Canon appeared in the printer window of my Airport Utility. Once I got the AEBS to see my printer, I then had to run Bonjour for Windows to install the printer.
http://www.apple.com/support/downloads/bonjourforwindows.html
Once the printer was installed, DO NOT attempt to print a test page, it didnt work for me, Im not sure if it works for anyone. I actually selected a couple of pictures and printed those to test its functionality.
http://tech.ifelix.net/1004.html
Not sure if you are on PCs or a Mac. The link above has some Mac solutions as well as a compatibility list of printers tested with the AEBS.
Anyway, hope this helps. I dont have my mac yet so my setup is dependant on PCs, so your steps might be different. There are plenty of threads around here that explain other peoples findings while setting this up. Just do a search and you should be able to find something if my info wasnt helpful enough.