Some online resources that provide free Dolch or sight words that can be printed are the Student Handouts, Teach-nology and K12 Reader websites. At the Student Handouts site, there are free printable flashcards containing 300 Fry sight words. Fry sight words are an expansion on the Dolch sight word list which are the most common English words that children need to learn.
Parents or teachers can print these words in groups of 100 that come 10 sight words per 10 sheets. This website contains many other educational resources for grade levels starting with kindergarten.
The Teach-nology site has Dolch sight words list for pre-kindergarten to third grade that are free to print. There also is a complete list of sight words available as well. Similarly, K12 Reader has Dolch lists with 220 site words available by different categories that are printable.