We are married filing jointly, zero itemizing, have two children and my husband works full time (anticipated yearly 45-50k) and I work part time (anticipated yearly 5k). How should we fill out our W4's? We would like to receive some back at the end of year, but not struggle each pay period with high tax deductions.

If you follow the directions for the W4 you should each put down;

1 for yourself
1 for being married
2 for your dependents
---
4 total allowances

Based on your wages of $5K the instructions indicate that you do not need to modify this number.

Instructions are here:
http://www.irs.gov/pub/irs-pdf/fw4.pdf