semi-noob question

Sounds like you need some idea of what "scale" is. 

Simply put, "1/35" means an object is 35-times larger than the model of it.  In a direct comparison (such as your "1-inch = 1-foot"), 1-inch = 35 inches in 1/35 scale.

Same for 1/32, and 1/48, etc. 

A Hornet-class aircraft carrier, at 888 feet in reality, would be 1/35th that in a model of that scale, or a little more than 25 feet.  A Sherman tank, at 19 feet in person, scales down to just over six inches long at 1/35 scale.

And to answer your other question, 1/35th is the dominant scale for armor, though 1/48 is rapidly gaining! 

1/16 is certainly geting more attention these days. THere are a number of vehicles and figures out there that are in this scale that could definately keep you busy.

Aircraft is pretty popular in 1/32. If you look hard enough you can still find some of the old Monogram 1/32 military vehicles. Not pretty but they are 1/32.

 1/35 is the most popular and will give you the widest lattitude for figures, accessories and vehicles. No planes but some helo's. The hobby is certainly focused on this scale and this is big enough you can get into some detail but small enough to not require a warehouse.

1/24 for alot of civilian vehicles and some aircraft.

1/48 is becomming popular again. Tamiya is certainly restocking the shelves with options. Figures are available from a few mfr's but no where near the extent of 1/35.

1/72-1/76 is the next most popular for selections of aircraft and vehicles. But may be smaller than you want to go.