My ex-spouse is delinquent in paying child support. The attorney general has filed some sort of paperwork with the IRS to withhold my ex-spouse's tax refund. How would I receive the withheld refund?

The answer is different for each state. You need to contact the state link to the U.S. Department of Health and Human Services Administration for Children & Families Office of Child Support Enforcement where you live to get this information.

Is there any way to find out if I need to file an injured spouse claim before I file a return?

Your spouse can ask the agency that might be claiming the refund for a past-due debt. Another source of information is the Financial Management Service Help Desk at (800) 304-3107.

Can I file my return electronically even though I am filing a Form 8379, Injured Spouse Claim and Allocation?

Yes, you can file electronically.