Chunky Monkey says, "Break the word down into smaller chunks. Look for parts you know."
Word families are groups of words that share the same ending. Once a child can read -at, they can start using the word chunk with different beginning sounds to read: rat, sat, mat, that, splat, etc.
Printable Resources
On her site, Michelle Hubbard provides many free early readers which can be printed out for home or school use.
Printable resources. UFLI offers text passages which grow in difficulty. New sounds and word chunks are introduced gradually.