Hi golfkaki,
Answer:
Set camera to timer mode, half press the shutter release to focus, press fully, then run to the row before the camera fires. No? :wink:
Ok ok, a more detail one. A few things to watch out:
1. Preparation - you will need decide how many rows of people and how many people per row that you want to arrange, and set up the benches well before the shoot. If you set up more rows, the back rows will get taller. Similarly if you set up less rows but fitting more people into one row, you'll probably need to set up you camera further away. Make sure the rows are relatively straight to reduce the chances of having people falling out of the DOF/flash range. You'll definitely need a tripod too.
2. In the list you mentioned, you are using an ultra wide angle lens (18-36mm equivalent). I'm not sure how is the linear distortion of this lens on the D70 (I own neither), but it would be good if you can watch out so that the people at the side/corner are not distorted.
3. If you are using the flash, make sure the distance from the flash to the last row of people is within the flash's range. It is probably a better idea to shoot without the flash or use it only as fill if the light is good.
4. Use a smaller aperture size to have sufficient DOF to cover all the rows. I would guess probably f/8 or above, and f/11-f/16 if there are many rows of people. Focus on the front row of people. Also make sure your shutter speed is fast enough to not cause motion blur when people are moving slightly (probably 1/60s or above). If needed, you can use higher ISO. I'm pretty sure the noise problem at ISO400 or below is very acceptable on your D70, even if you intend to blow up your prints. Or you can shoot raw and do the ISO adjustment later.
5. Take more then one shot. With so many people, there will definitely be some who are not in ideal condition (blinking, etc) when the shutter is released. You might want to refocus each shot just in case some shots are not as sharp.
Ok... that's about all I could think of. Hope I've answered your question.