It's tough to hire resources for contract assignments.Here i would like to share some of my thoughts. 

People who have done higher studies and returned from abroad

People who returned from abroad after working for some time. They possess good domain experience.

People have taken break for Family reasons – pregnancy, raising kids etc. In just matter of time.. they will come back and do well on the job.

Failed Entrepreneurs – Can create win-win situation for these folks.

Freshers – This is great pool. Identify folks who got trained on skills. Can be useful for short term projects.

People who have taken break for personal reasons- accidents, loss of death in the family. It will be a good opportunity for them.

Bench folks – Corporates builds 15-20% work force of bench folks.

Build a good database of training Institutes – skill based. Can be useful for short term projects

Effective use of online Blogs and Job Postings -Social Media

People passionate about field – they do not mind as long as it is a good opportunity.

Of course .. Job Portals is good source of contract resources.

I value your views.