Entity Tool- One of the most important tools the Entity Tool allows you to place entities such as info_player_start ~ player spawns.If you look at one of your 3 grids while using the Cam tool, you can left click then drag the mouse to set a perspective point. Camera Tool- This tool is helpful as it allows the mapper to get a 3D perspective of his map (You can change between what the Camera tool renders in the View menu bar.) Left click to alter where the camera is facing, and right click to strafe the camera.Using the mouse wheel while using the Camera tool zooms in and out just as much as this tool does. Magnify Tool- Once again another self-explanatory tool.Selection Tool - The selection tool is helpful as it has the ability to select objects, entities, and so on (hence the name).Get familiar with the tools you'll be working with.