There isn't a lot of time to teach this unit, maybe one week. It's only one page of SOL material, but it's jammed with facts. As a reminder, students will have learned about Jamestown and Puritans before, but in 6th grade. You may want to brainstorm with students about what they might remember from 5 years ago. You could also open with a primary source document or chart showing the population changes in Jamestown.
http://www.digitalhistory.uh.edu/historyonline/lesson_plans_display.cfm?lessonID=23
SAS Curriculum Pathways: Quick Launch #29