There a lot of free programs to help you with graphic design. Here are some good ones to start with.
Photo Editing
Paint.net - An image and photo editing software for PCs that run Windows
GIMP - Software for photo retouching, image composition and image authoring
Graphics
Inkscape - A professional vector graphics editor for Windows, Mac OS X and Linux
Sketchpad - a simple tool for creating digital art and images.
HTML
BBEdit - Basic HTML editor for Macs
Notepad ++ - Basic HTML editor for Windows
HTML Kit - Basic HTML editor for Windows
Fonts
Google Fonts - a directory of web fonts that allows users to browse and preview fonts
Color Tools
Color Picker - HTML Color Picker
Hex Color Scheme Generator - Tool that shows you matching colors for your site
Color Scheme Designer - A designer tool for creating color combinations that work well together
Get Colors from Image (BETA) - Simple tool that get colors from any image
Check My Colours - Tool that tells you if your website design is accessible
For iPads
Adobe Illustrator Draw - An app for creating illustrations that can be sent as layered files to Adobe Illustrator CC or as flat images to Adobe Photoshop CC