Here are a few resources that have proven helpful to me:
Companies Offering Multiple Births Programs (Work in Progress) - This is a master list of companies offering gifts to multiples. You must present proof (birth certificate or hospital discharge papers will suffice) but we have received several nice gifts from companies thus far. My recommendation is that you find someone to do these letters early in your pregnancy then all you have to do is send in the appropriate documentation. I got a late start on it because I was too proud to ask for help so I'm still awaiting some responses.
Feeding Chart - This is probably one of the handiest resources we've used! Adapted from a version from another quad mom (Four to Adore), this chart uses columns to record how much formula each baby drank, what time, and whether they had a wet or dirty diaper. It's hard enough to remember how much formula one baby drinks and when he or she had a dirty diaper, let alone four. So it's important to write everything down! Feel free to adapt your own version of this chart as well.
SSI (Supplemental Security Income) for Premature Infants - This post outlines some of the information I learned through the process of applying for SSI after our babies were born at 28 weeks gestation with low birth weights. I'm also happy to answer any questions I can for parents faced with a premature infant. Please feel free to contact me using the "Contact Us" on the main page of my blog.