Order CBC (complete blood count) blood testing online
In the majority of US states you can order CBC testing online and have the blood drawn at a local blood draw center (see my general overview of the process).
I'd suggest ordering from Walk-In Lab because they have the cheapest price I know of ($28), and I've been happy with their service. You can also compare the other 6 CBC test providers I've found.
Take a look at my state-specific issues page if you're in AZ, MD, NJ, NY or RI.
Understanding the results
The American Association for Clinical Chemistry has helpful pages for understanding the test and answering common questions.
Optimum level of neutrophils and lymphocytes
I don't know the first thing about neutrophil and lymphocyte levels, but I saw this study that implies to me that high neutrophils and low lymphocytes are associated with bone density loss.
Optimum RDW levels
Mike Lustgarten suggests that red blood cell distribution width levels under 13% are optimal for longevity.
Sources for CBC testing without differential
Some of the providers I found had CBCs available without "differential" (testing for types of blood cells). It looks a little cheaper depending on which provider you choose.
Show no-differential sources
If you're interested in self-testing as I am, check out my Facebook or Twitter account where I post interesting self-testing news and get a little too excited about blood test sales.