For more ways to reduce expenses:
1) Use craigslist for furniture. I have small kids (the 2 year old has decorated practically each and every wall) and there is no way I am going to purchase very expensive or even expensive furniture just to have her draw or crap on that too, I have been able to find great deals on craigslist. At the same time, look around the house for things that you do not use anymore and sell them to make a few extra bucks.
2) Buy clothes on consignment. They are in good condition and much lower than retail
3) Don't buy books, rent them. Or borrow them from the school's library. If the current issue is 4th edition but the library has 3rd edition free to loan then who cares. My wife is a book editor and trust me when I tell you that the differences between 1 and the other very minor.
4) If you would like to get some cologne, go to Macy's and ask them for any samples. They are small but ample enough until the next sample is available. Store brand like CVS/Walgreens for your typical meds like ibuprofen, omeprazole, etc. Shampoo/soap/shaving cream.
5) Public library. Excellent place for borrowing books to read for pleasure, newspapers, and they usually have a lot of free activities for the kids.
6) coupons, coupons, coupons, coupons.
7) Search your town's, county, or state website for free events to take the kids.
8) Have a dinner out with the kids at a park. Pack a picnic.
9) When going out with your wife, eat dinner at home but make desert your date night. Or, take her out to lunch. Both let you get out but the cost is much more affordable than dinner.
10) Coffee houses usually have open mic night, free entertainment with your coffee.
11) Be meticulous at the store. Sometimes you need to spend more time comparing prices and when you are at the register pay attention. Yesterday I bought school supplies and was getting charged $0.50 more per folder than I should have. Small change until you buy about 20 of them like I had to.
12) When doing your taxes, claim everything you can. You should not have to pay federal income taxes because you are below poverty level, but if there is childcare, claim it. If you sent your kids to camp that is considered child care, claim it. Education expenses claim them. Of course talk to an accountant first lest you be in trouble with the man.
13) Don't be afraid to ask. When I was shopping for suits for residency interviews I went to a store for their 2 for 1 sale. When they did not have my size (I am a bit on the husky side), I spoke with the manager and explained that I was a student and going to job interviews and was wondering if they can do anything to help me out. They gave me a 10% discount per item. Don't be afraid to ask for discounts, what is the worse they can say? No. Then you are no worse than before.
14) Find out where the price of gas is lower if you pay cash and pay cash.