Handwriting For Kids has manuscript (block lettering) and cursive practice worksheets for letters, words and sentences. Worksheets are available for right-handed and left-handed writers.
There are articles and advice for teaching handwriting, penmanship and helping learning disabled students improve their handwriting. There are a few worksheets available in Spanish.
You can customize some worksheets to include pictures, including pictures of American Sign Language signs for the alphabet.
Be sure to check out the animations for writing cursive lower case letters.