Dolch words, 220 most frequently used words in reading, are important for a child to have success in reading. I do put an emphasis on learning these words to where a student can read them quickly and with no difficulty. Below are some websites that serve as resources.
Jan Brett's Dolch Word website http://www.janbrett.com/games/jan_brett_dolch_word_list_main.htm
The School Bell is a wonderful website for Dolch words and activities. Be sure to scroll all the way to the bottom of the page. http://www.theschoolbell.com/Links/Dolch/Contents.html
Quite a thorough website for Dolch words by Mrs. Perkins, a 1st grade teacher. http://www.mrsperkins.com/dolch.htm
Find out about Mr. William Dolch who came up with the Dolch word lists. http://www.dolchsightwords.org/