as far as I know using a simple IR filter like the Hoya R72 will do you almost no good as the sensor (like all sensors) has a IR blocking filter on it. you would have to do
very long exposures to get any type of decent results. to get proper IR results the sensor has to be modified to allow IR to pass through. this is not cheap or easy and really requires the purchasing of a dedicated body to do this as you cannot revert back. then you must purchase an IR filter such as the above mentioned Hoya R72 for the best results. whether film or digital, IR is an undertaking for sure. there just isnt an easy (or cheap) way to get IR.
Im sure others with more knowledge and expeience will chime in, but here is a good site fot reading up on IR phtography. it also has a list of links at the bottom that will llikely be very helpful.
wrotniak.net: Infrared Photography with a Digital Camera