[UseThePeenEnd]

I killed the informal games in college but did not play again for over 20 years.

a year or so ago, at age 46, I watched TV, read a book, bought in $100 and ran up to $250 immediately playing .5/1 and decided I should turn pro...

Of course I then went broke. Read everything I could find, played play money, played the Turbo software, and bought in again. I then fluctuated for awhile, but began to win modestly but steadily.

I bought Poker Tracker and a poker library from my winnings and used player view (it was free then, and still is for use on a single table). I played 1/2 very briefly while watching a lot of 2/4 (loading observed hands in Poker Tracker) and reading this forum. I then moved into 2/4, then started multi-tabling.

Ive been very cautions with my bankroll. I presently have $4200 after paying for software and books from my bankroll and playing a few hours a week, and am still only cautiously moving out into 3/6. This is probably more careful than you should be, but I, like yourself, intended to never have to put any more money into the game after that second buy-in.

What helped me most:
Poker Tracker is an absolute must.
TABLE SELECTION AND RELATIVE POSITION ARE PROBABLY AS IMPORTANT AS YOUR ABILITY.
Player View is extremely useful once you start multi-tabling.

Reading: Small Stakes Holdem, Holdem For Advanced Players, Theory of Poker (all by Sklansky with collaborators).
All excellent.
Lee Jones and Lou Krieger: their books have some useful material, but they basically reinforced my early (and recurring) weak-tight tendencies.
Phil Hellmuth: awful trash. 300+ pages of "aint I great?"
Ken Warren: utterly useless, other than a nice section of odds and probability in "Ken Warren Teaches Texas Holdem".

The new book by King Yao is also superb.
I have never read super System, so cant comment.

Learn something besides holdem. I am horrible at stud, so I tried Omaha high-low and there are more crossover insights than you might think, and it is a great change of pace.