When you first pull up the Unit Design area you are greeted with a screen that looks like this:
There are only 2 units listed on this screen when you first start playing. After you design your units and save them, they will be listed here as well in future games, provided you have the prerequsite technologies that you had when you first designed them. For example, if your saved scouts from a previous game are equipped with forged vambraces, then you will not be able to see them here until you have researched the appropriate technology to unlock those.
Here is the other unit type currently available, the Basic Guard
The number of hitpoints the unit has when built.
The attack strength of the unit. Modified by changing weapons or by a Band of Might.
The current armor of the unit. Modified by changing types of armor or by a Band of Fortitude.
From looking at the unit's .xml file, this appears to be the attack speed of the unit. If so then higher is a better number.
How many movement points a unit has.
How many gold pieces per turn it costs to maintain the unit.
Turns to build
How many turns it takes to build the unit with 1 barracks in a given city at the basic experience level. Note that at this time multiple barracks stack in regards to build time for units. This is modified by the type of equipment that you give a unit (it takes longer to forge a breastplate than to go unarmored, etc). Note that this will be the base build time for the unit. If you choose to train a veteran it will add to this time. Also note that every piece of equipment that you add that increases build time stacks. I.E. if yo add 5 pieces of armor/weapons/equipment that each add 2 days, then you have just added 10 days to the build time of the unit.
A shot of the equipment tab and the Band of Fortitude