As of July 31, 2010, the Chicago USCIS office reports that it is taking approximately 4 months to process I-485 Adjustment of Status applications (which would include the underlying I-130 in AOS cases). You can see this at: https://egov.uscis.gov/cris/processingTimesDisplay.do.
That's fast! As far as checking your receipt number against the online status page, sometimes they just don't get the receipt number loaded in... ever. Other times, it might be in their automated system but with faulty information or dates. It's definitely not 100%. You can always call the National Service Center 1-800 # listed on your Receipt Notice, but I'd give it at least 30-60 days before bothering as it will just be in the works until then. You should receive a biometrics appointment notice within several weeks of applying.
For assistance in preparing adjustment of status application packages and removal of condition on residence petitions, conducting case status inquiries, and filing FOIA requests, contact Ms. Amy L. Becerra, Esq.; (757) 345-9019; email@example.com.
The files will be forwarded to your local USCIS office after the beneficiary submits to biometrics. The employment authorization document (work permit) will be issued within 90 days of reciept of your application.