Welcome to The GIMP ! Nearly all image operations are performed by right-clicking on the image. And don't worry, you can undo most mistakes... You are so very lucky to be using this excellent program. You can get context-sensitive help for most of the GIMP's features by pressing the F1 key at any time. This also works inside the menus. The GIMP uses layers to let you organize your image. Think of them as a stack of slides or filters, such that looking through them you see a composite of their contents. You can perform many layer operations by right-clicking on the text label of a layer in the "Layers, Channels and Paths" dialog. When you save an image to work on it again later, try using XCF, the GIMP's native file format (use the file extension .xcf). This preserves the layers and every aspect of your work-in-progress. Once a project is completed, you can save it as JPEG, PNG, GIF, ... The layer named "Background" it special because it lacks transparency. This prevents you from adding a layer mask or moving the layer up in the stack. You may add transparency to it by right-clicking in the "Layers, Channels and Paths" dialog and selecting "Add Alpha Channel". Most plug-ins work on the current layer of the current image. In some cases, you will have to merge all layers (Layers->Flatten Image) if you want the plug-in to work on the whole image. Not all effects can be applied to all kinds of images. This is indicated by a grayed-out menu-entry. You may need to change the image mode to RGB (Image->Mode->RGB), add an alpha-channel (Layers->Add Alpha Channel) or flatten it (Layers->Flatten Image).