If you want to make an avatar animation then you will need a software for that. There are two softwares I can recommend you.
One of the softwares you can use is paint.net it's free to download from thins
link.Its user friendly and less complicated from photoshop, but when it comes to layers you have to make one for yourself cause its not like photoshop that when you paste an image it is place automatically in a new layer. And if you use this, you will have to save your frames piece by piece as gif cause it can't save an animation directly. After saving your frames you can put them together in another software called unfreeze which can be downloaded
here. In my personal experience with unfreeze, you can't set the delay for your frames so what i did was this, for example I made a breathing avatar I place three frames each in there just for the delay (frame1x3,frame2x3,frame3x3,frame2x3 then loop).
The second software you can use is of course adobe photoshop. This is more advance compared to paint.net unlike paint.net. You don't have to worry about making another layer when you paste an image. You can also save your animations directly without the use of unfreeze, just click edit in image ready or shift+control+m then you will see a window there called animation. You can make your frames there and just arrange the layering by frames, after that you save it for webs-> file>Save Optimize As or control+shift+alt+s (thanks for teaching me this sindeyella).
Thats it, I hope this helped you guys and if there are other softwares you're using please post it and how you do your animation in it. Have fun animating