The story portrays the lives of several school girls attending a Japanese high school with a very loose humor tone. The serialization began with the four main characters in the first year of high school. As the years progress, they move onto their second and third year.
Lucky Star manga is still being translated, 5 volumes are out but they are not translated to English yet so I will just post it as 5 chapters per link until this volume is finished and the other volumes are released in English then can post it in volumes.
Chapter 1-5: http://www.megaupload.com/?d=JZOW1UHG
Chapter 6-10: http://www.megaupload.com/?d=O9K2FKFP
Chapter 11-15: http://www.megaupload.com/?d=BJ29H6Q1
Chapter 16-20: http://www.megaupload.com/?d=PKEF97HQ