Destiny: What Is a Raid Lockout? How Does It Work?

For people that haven't raided before this is a pretty good explanation of how things work with raiding.

Interesting info here.  Side note - First, this is still speculation so take that info with a grain of salt.  Second, you can do at least two runs per week: 1 Normal, 1 Hard. And third, Remember if this is true, you can run with one group with one character and another group with another character.  As long as your characters are lvl 20.

Example - Sticky runs with some bros with his Titan.  Huskers group needs a 6th member in a different group.  Sticky can run with his Warlock with that group no problem.

Good point about using different characters that will help.  I definitely plan on getting at least 2 characters to the point that they'll be able to raid.  My 3rd will be my "casual" hunter to just slowly build up.