To use Komodo’s Quick Bookmarks you simply need to set one at a line of code you need to reference for later. Use the default key binding (ctrl + shift + [0-9]) or right mouse click context menu in the editing area.
When you want to jump back to this location again at a later time use the default key binding (ctrl + [0-9]) or the right click context menu in the editing area. You may note that there is no Go-to option for all the bookmarks. This is by design; they are not shown until they are set which saves you from cluttered menus.
I use quick bookmarks on a daily basis while either tracking down reported bugs or researching a new feature that works on top of an existing feature in Komodo (like when I was writing Quick Bookmarks) and you should to.