if you grind the wheat berries and use what is ground, you have whole wheat flour, but to get white flour, you need to sift out the bran and germ?
As has been stated, this is
true whole wheat flour. I don't think you can sift out the bran and germ at home (why would you want to

). It requires special equipment.
I also read that freshly ground flour must be aged at least a month to be effective in baking; is this truth or hogwash?
It's hogwash! I always use my flour as fresh as possible, often grinding just before baking. Why? A kernal of grain is a living thing. Once you break it open by grinding, it immediately begins to lose nutrients, similar to the way garden produce begins losing nutrients as soon as you pick it. For the optimum nutritional benefit, it should be used before 72 hours. I have always had better results by using fresh flour.
The fresh flour produces a denser loaf.
This has never been my experience. In fact, the opposite has been my experience, and I have been doing this for 21 years. But, as stated before, everyone has different results, so try it if you want.
Grinding your own flour, and using it fresh, is one of the best things you can do for yourself and your family. It truly is healthy eating! Congratulations on your plan to purchase one. I highly recommend the Golden Grain Grinder
http://goldengraingrinders.com/. It is more expensive than some of the others, but is better built and comes with a 5 year warranty! Nothing else touches that. It is my 4th grain mill. I burnt up the other 3 after just a couple of years.

I purchased the extended 10 year warranty, and hope this one lasts at least that long. I have had it a year, and so far am pleased with it.