Let's assume your project consists of 4 tasks: Task A, Task B, Task C, and Task D.
Task A (first task for the project, takes 2 days) starts on January 10th 2011, its early finish is January 12th 2011 (morning), and its late finish is January 14th 2011.
Task B has Task A as its predecessor, and its early start (ES) is the early finish of Task A (since it is the predecessor), so it will start on January 12th 2011. Task B takes 5 days to complete, which makes its Early Finish (EF) January the 19th (morning).
Task C has Task A as its predecessor, and Task C's duration is 1 day. The early start of Task C is January the 12th, and its early finish is January 13th.
Task D (takes 3 days) has both task B and task C as predecessors, in this case, the ES is the longest EF of the two predecessor tasks, which is Task B, so Task D early start is January 18th, and EF is January 21st (morning).
The critical path is Task A Duration + Task B Duration + Task D Duration = 2 + 5 + 3 = 10