Hello western 1688, welcome!

A flatbed scanner is probably the best piece of equipment to use with getting good stamp images.
The higher resolution or pixel (point) count on here are done with a higher setting on the scanner.
Low res pics can be scanned at 100 ppi (pixels per inch) but higher res pics can go up to 600 or even 1200 ppi if you are really looking for those hard to see details. Takes more room on computer and web site though as more pixel depth.
A camera is good for getting shots of phosphorescent tagging on modern stamps as scanners usually can't pick this up. Or for getting shots of rooms, desks, catalogues, books, albums from a distance or close-ups with the newer cameras.
The programs that allow you to crop photos or scans to remove extra empty backgrounds bits, are also important. There are some free programs that can do a good job at this but your scanner or camera usually comes with programs on a CD or DVD to load into your computer. These are usually good enough for regular stamp scanning and such.
To get to designing your own album pages and maps and such then some fancier software (programs) is required usually.
I have a Hewlett Packard flatbed scanner that can take a full Vario plastic stock page (8-1/2 x 11 inches) (A4 international size roughly) and the old software that scans and crops and edits the photos / scans, I like better than the newer 'improved' versions of it.
Google has a photo editing program that you can download for free called Picassa I think. Need you screen set to a higher resolution for that than is good for my eyes but it is a nice program really.
edit to fix typos and add a paragraph.