The dRebel is (almost) no different than other Canon EOS camera (film or digital). It can accept any EF mount lens (from Canon or third party). The dRebel is particular because it can also accept EF-S mount lenses, but by now the only EF-S lens is the EF-S 18-55 already included in the kit.
EF is a mount specification, defined by Canon. It encompass both the mechanical mount (diameter, bayonet type, electric contact position, etc) and the protocol between the lens and the camera body. Only EF lenses work in EF mount bodies (Canon EOS ones, digital or film). This has nothing to do with the fact a lens is AF (autofocus) or MF (manual focus, as some macro lenses). There is AF and MF lenses with an EF mount (the only that work in Canon EOS bodies), and AF and MF lenses with other mounts, as the old FD Canon mount, or other camera brands ones (and they dont work in an EOS bodies). Of course they are EF-mount lens from Canon and other brands, but other brands use a common name for lenses because usually they made versions of the same lens for different mounts, so they use phrases like "for Canon EOS bodies" or "for Canon EF mount" instead of use the EF part in the name.
Bottom line: you need an EF-mount lens for your Rebel, and only an EF mount one (Canon or other brand). The problem with non-Canon lenses is as Canon doesn't disclose the protocol used between lens and camera body, only Canon lenses are 100% compatible with past, present and future bodies. Other companies had reverse-engineeered this protocol, but usually old lenses have problems with new bodies.
When lens incompatibilities are found, the camera displays an "Err99" message in the display and stop working. This is a common problem with old third party lenses in new Canon bodies (film or digital). It's lens fault. It doesn't happen with brand new lenses. At least in Sigma ones, you must return the lens to the manufacturer. They'll rechip the lens to work fine in the dRebel.
This is an extract from SigmaUSA lens FAQ:
Q: Are Sigma lenses compatible with my new Canon Elan 7 camera? The Rebel Ti? How about EOS 10D.(you can read EOS 300D/Digital Rebel here too)
A: All current production Sigma lenses for Canon autofocus cameras are fully compatible with the new Elan 7, Rebel Ti or EOS 10D camera. This includes all HSM type lenses. Some earlier production non-HSM lenses may require modification in order to perform normally with the new camera. If you have a question about a particular lens, please contact Sigma's service department (in the U.S.) at (631) 585-1144 or via email at info@sigmaphoto.com.