Some of them might be suitable for the younger students.
http://www.sundhagen.com/babbooks/
http://www.rif.org/kids/readingplanet.htm
http://www.bbc.co.uk/cbeebies/fimbles/comfycorner/index.shtml
http://www.bbc.co.uk/cbeebies/stories/
http://www.the-office.com/bedtime-story/indexmain.htm
http://pbskids.org/lions/stories.html
http://www.eastoftheweb.com/short-stories/childrenindex.html
http://www.magickeys.com/books/index.html
http://www.tampareads.com/books-ol/index-ol.htm
http://ivyjoy.com/fables/index.shtml
http://www.mightybook.com/
http://www.kinderstart.com/frame_for_links.php?redirect=http://www.fun4allkids.com
http://www.ziggityzoom.com/stories.php
http://www.kidskorner.net/stories/
http://www.netrover.com/~kingskid/108b.html
http://www.storyactive.com/stories.htm
http://www.petakids.com/comics.asp
http://www.dandi.me.uk/
http://www.schoolexpress.com/storytime.php
http://www.sesamestreet.org/home
http://www.storybookcastle.com/books/
http://www.storyplace.org/preschool/preschool.asp?themeid=21
http://www.grandfatherreads.com/pig%20story%201.htm
http://www.sundhagen.com/babbooks/grow/index.html
http://www.apples4theteacher.com/short-stories.html
http://www.storyit.com/Classics/Stories/aesop.htm
http://www.highlightskids.com/Stories/Timbertoes/h13TTArchive_Holidays.asp
http://bygosh.com/
http://www.kidsgen.com/stories/
http://www.babybumblebee.com/company/freebies.cfm
http://www.ability.org.uk/kids_and_teens_online_stories.htm
download stories
http://juniorsbook.com/kids_activity_list.asp?category=Download
http://www.oxfordowl.co.uk/Teacher
pronounciation
http://www.starfall.com/n/level-a/learn-to-read/load.htm?f
Macmillan children readers or macmillan Education, - Oxford Dominoes starter or Dolphin readers - Richmonds modern readers are very good too.
Here is the site for Pengouin readers
There is an other site called Reading zone, you have to be a member and pay for it, but once a year they open the site and you can download lots of books.And you have some free samples the whole year.