@Matthew -- there's a lot of research on email best practices but it really is specific to each client/product combination. A good starting point is Predictable Revenue:
It will give you a basis for starting your first email programs -- (in a nutshell, for cold emails into big enterprises, go senior in terms of the target, go REALLY short on the emails, ask for a referral to the right person).
I'd also recommend getting started with a template system with tracking. In particular, Yesware does a great job on this front -- if you've the money, splurge on Yesware + Salesforce licenses so you can track these conversations and measure which ones turn into something.