How to write a Script to run series of batch jobs on unix platform

Im new to unix shell scripting, I have to run batch jobs on unix. for example i have 5 jobs. first 2 can kickoff parallely. after completely finishing the 2 previous jobs the 3 job should kick off..once 3rd is over 4 th and 5th can kick off parallely. Each jobs run for 1 or 2 hours each.

How to write shell scripts for this task. Is perl will be more efficient for this purpose.

Please help me with answers.

Check out subshells:
http://www.tldp.org/LDP/abs/html/subshells.html

Thanx for reply and help.