Picture editing and management is supported by many great free programs, for any job, simple or not.
The first application we need, I guess, is a viewer / browser of images, that will let us select, delete, decide which of them to edit or e-mail, etc. Even if I know exactly what to do with certain pictures – edit, retouch, etc- the first thing I want is just to open and have a look at them. For this task a heavy editor is not the best option. After trying several image viewers advertised as “fast” and “simple”, such as XNview or MyViewPad, I found really fast and simple the default image viewer of Windows. For some more power, get IrfanView.
You can invoke your heavy image editor right from the Windows viewer or from IrfanView, if you usually do complicated editing; if you need to retouch a little your photos, you can invoke a lighter editor.
PhotoFiltre is a relatively fast, although complex enough, image editor, having also some useful browsing capabilities. It will let you perform easily retouch jobs, and it can also proceed to the next picture in the folder by just the pageup and pagedown keyboard keys, which means that once you open PhotoFiltre, you can continue viewing your pictures with it, instead of using again the default Windows or any other image viewer. See How to use PhotoFiltre and check also Paint.NET, another free, fast, easy to use and powerful photo editor.
PhotoFiltre or Paint.NET will be great companions since they are fast, easy and powerful enough, especially when you need only to retouch, apply effects, etc. For a PhotoShop alternative, a heavy editor that will let you perform quite complex editing, you can try (what else?) GIMP.
Conversion of pictures from some format to another can be an everyday task. What worked for me the best was a right-click option: Instead of having to open some of my photo editors, it proved faster and easier to just select and right click on these pictures as I see them in their folder and convert them at once. Morz Image Converter will do just that, supporting a lot of picture formats.
Picture Resize can also be an every day task, – if you send pictures by email all the time, etc. Microsoft’s free Image Resizer powertoy will install a right click option to let you easily change one or many pictures just while you see them in their folder. It includes the options of saving them in different names or not, and of using one of 3 main default sizes or define a custom size you might want.
If you need to manage / index / organize your images, perhaps the best free solution comes from Google, with Picasa. Picasa offers also some retouching options, but you wouldn’t install it just for them.
Besides these programs, there exist also applications to perform single special tasks, such as optimization (reducing the quality of an image without visible changes), photo morphing, etc. You can find such utilities in the Graphics section.