Most of the Circuit Courts have posted their docket sheets on the Web. Links to those sites are available from the LLRX Court Rules, Forms and Dockets, the PACER Service Center and on Legal Dockets Online. Otherwise, you can use PACER, CourtLink, CourtExpress, or get the docket sheet from the court.
The Ninth Circuit Court of Appeals' website includes recent opinions and some case information. Coverage is more comprehensive for key cases of interest. There is also some video and audio recordings of oral arguments available. Most dockets and filings, however, will only be available on PACER.
The other circut courts' websites are available below. Each will contain varying information but will generally include recent opinions. Some circuits do make selected oral argument recordings available on their website.
1st Circuit Court of Appeals (Oral Arguments available 2008- )
3rd Circuit Court of Appeals (Oral Arguments available 2007- )
4th Circuit Court of Appeals (Oral Arguments available 2011- )
5th Circuit Court of Appeals (Oral Arguments available 2008- )
7th Circuit Court of Appeals (Oral Arguments available 1994- )
8th Circuit Court of Appeals (Oral Arguments available 2000- )
9th Circuit Court of Appeals (Oral Arguments available 2005- )
District of Columbia Circuit Court of Appeals
Federal Circuit Court of Appeals (Oral Arguments available 2006- )
U Chicago Law Library - Federal Courts