FREE - In Google Play
FREE - in Win Phone Store
Chess.com has provided an intuitive and self-explanatory procedure ...
MY HOME, Photos, Create a photo album.
Supply a name for the album and a description. Click on SELECT PHOTOS.
Click on CLICK HERE TO UPLOAD PHOTOS.
Select one or more photos. Click Open. - depends on which OS you are using.
Click on UPLOAD MORE PHOTOS or SAVE & CONTINUE.
This album is currently not published. You must click the "Update & Publish" button below to allow others to view your photos.
Click on UPDATE & PUBLISH.
Rael, TheGrobe et al have provided detailed instructions here (http://www.chess.com/forum/view/help-support/screenshots) on editing images and using them in forum posts.