Hi there,
For a start, you need to know if you camera is capable of doing IR or not. Since you are using a Nikon D70s, it is capable of IR. The next step will be to get an IR Filter, there are quite a couple of the IR filter out there, but the common one are the Hoya R72 and Cokin P007.
The main thing that you need to know is how to set you CWB (Custom White Balance), please see this
thread if you are not sure.
You can read this
thread posted by Max2.8 on how to do IR Photography.
I have actually come up with my own work flow based on Max2.8, Teerex, photoexpress and others guidances. Others may have a different style and work flow.
Just to share my flow here.
1. Set the White Balance using some green grasses or plants with the IR Filter ON
2. Ensure that Custom White Balance is set properly then remove the IR filter
3. Exposure Compensation set to +0.7 or +1.0 or more (depending on condition)
4. Set to Aperture Priority Mode using F8
5. Try shooting in the opposite direction of the sun
6. Compose the shot first, then switch Focusing to Manual (Camera on Tripod)
7. Put on IR Filter and lens hood to prevent flare
8. Cover viewfinder and trigger the shutter release
9. Do Pro-processing