If you scan . . .
Scanning in the visual arts lab is performed through Photoshop.

File menu, Import, select ScanWizard 5. 
Settings can be changed to scan color, grayscale, line art, etc. (line art means black and white)

Color on a computer monitor is RGB, eight bits per channel for a total of 24 bits. Grayscale uses only one channel and is therefore, eight bits. Line art, (also called threshold or bitmap) is only one bit. As you can see color will take more memory space and require bigger files.

Default resolution is 72 ppi, (pixels per inch). For web use, this is fine. For print output more ppi makes for better quality. 

For simple course work an output of 150 ppi to 200 ppi is all that is usually necessary. For commercial output 300 ppi to 400 ppi would be used. Resolution quality is tied to size. If something is to be enlarged, it would require more ppi. If reduced in size, less ppi would be required. 

For example: if you had a 1" image at 300 ppi (pixels per inch) it would look pretty sharp. If you enlarged it to 5", you still only have 300 pixels of information, you have just enlarged the pixels to spread out to 5". The resolution of your new image is now 60 ppi and would have "the jaggies" and look pretty coarse.

For print quality a general guideline is to scan at twice the LPI of the halftone screen that will be used to print. For 150 LPI halftone screen scan at 300 PPI.

Place original in scanner, (be careful not to scratch the glass), select overview to take a low res scan of the entire scanner bed. Use the marquee selector tool to isolate the area you wish to scan (scanning unnecessary area takes longer) then select scan.

You may be asked to select where the scan will go. If you are going to use it in Photoshop, select a file location and TIFF or PSD as the format. You can then open in photoshop where you can adjust and re save it.

You can gang images (group together) to cut down scanning time, then separate them in photoshop. You can easily rotate images in photoshop if they were not straight in the scanner.

NOTE: Many scanners can also scan transparencies (slides). If your overview window is black, someone may have forgotten to reset for reflective copy.