It's not easy identifying an asteroid image (especially a faint one) in a CCD frame that may have dozens if not hundreds of stellar images. Thus, we have to use the fact that asteroids move and compare two or more frames taken at different times to spot our target. Generally, a 15 to 20 minute interval is sufficient to spot asteroid motion when two images are aligned and blinked using JIMSAIP. I usually take 6 minute exposures which will usually take me down to 18th magnitude or better. We can't use exposures much longer because the asteroids will trail excessively. Given the time needed to download the image, apply dark frame subtraction and save the image (after a cursory examination to see if there are any comets in the field <g>), I usually take three exposures as fast as I can. The two end exposures are separated by the right amount of time and the middle exposure provides backup. I have also found that the third exposure provides confirmation of suspected 'new guys' and the technique has often saved me from wild goose chases after non-existent 'new guys'.
I prepare finder charts of my selected targets (see Strategy using Guide (latest version) from Project Pluto. I set Guide parameters to display a one degree wide field (with a 1 degree circle drawn) and have the CCD frame parameter set at my CCD FOV (35x23 arcminutes). I set it to show the faintest stars possible (generally down to 15th mag). I print the chart with the target in the center. (However, see the new writeup describing use of the LX-200.)
At the telescope using the NGC mini-MAX and calibrating on a nearby star, I can usually place the camera view somewhere within the one degree circle. A focus frame of 2-5 seconds will usually show every star on the finder chart. It is then a matter of identifying the displayed image with the finder chart to see how much and in which direction to move the telescope to center the desired field. I orient the camera on the telescope to give North at the top and East at the left, which is the orientation of the finder chart.
With the ST-7, it is necessary to locate a guide star for self-guiding. Sometimes this is difficult as periodic errors in the drive of the Meade are so bad that I am limited to less than 5 seconds integration time. There have been times when I have had to abandon a target because I couldn't find a suitable guide star. These occasions have been rare, though. If I am looking anywhere close to the Milky Way, there are plenty of guide stars.
All images are saved to a separate directory. I have a CCDIMAGE directory which is further sub-divided into directories named for the date in yymmdd format (e.g., 970224 would be Feb 24, 1997). This keeps them in sorted order (oldest first) for easier navigation later when doing the data reduction.