To begin designing web graphics in Photoshop, concentrate on learning tools such as layers, the selection tool, and layer masks. Start by understanding how to adjust image sizes to web-appropriate dimensions and save them in suitable formats (e.g., PNG for transparent graphics, JPEG for photos). Try designing banners, icons, and various web components. Moreover, get to know Photoshop's guides, grids, and smart objects for accurate designs. Many online guides can assist you in creating web graphics gradually.