I use RIA's Checkpoint, but it is a pay-for-subscription site.
You can subscribe to RIA's Checkpoint online (http://www.RIAhome.com and
http://www.RIACheckpoint.com). It offers three levels of pension and benefits libraries, each one of which includes the Form 5500 forms, eform-RS for completing forms, and Compliance Explanations, which details how to complete a Form 5500 for a stock bonus plan or ESOP. Right now, it is offering a30-day free trial to check any of them out (and determine if you really need to buy the product). If you decide to buy, the price is somewhere around $1500 to $3300 per year, depending on the product.
The subscription also would give you several other publications providing pension and benefits analysis, the Code, regs, ERISA and regs, and agency releases.
If you want print, there are Employee Benefits Compliance Coordinator and PPC's 5500 Deskbook, both in looseleaf. Both are available through the same websites.