If I wanted to read NF where would be a good place to start other than the very beginning?
PAD purposely jumped the action forward three years, to give new readers of "New Frontier" a clean start. So you could pick up "After the Fall" and "Missing in Action". And then you'll be ready to read the upcoming IDW comic mini-series.
However, I loved the timeslip arrivals of TAS characters, Arex and M'Ress, in "Gateways, Book 6: Cold Wars" - PAD had some major plots in mind for these characters when he used to write a TOS movie-era comic for DC, but in 1989 he had to remove the TAS characters for licensing reasons. So you could start NF here, with "Cold Wars" (keeping in mind that some people don't like the humour in "Cold Wars" much) and then continue with "Being Human", "Gods Above" and the amazing "Stone and Anvil". Then the arc jumps the three years to the aforementioned "After the Fall" and "Missing in Action".
If you like quirky ST characters, "New Frontier" is where you'll find them.