Links to websites that provide notes on bidding contions:
ACBL (American Contract Bridge League)
bridgebum
bridgeguys
the Bridge Burglar
Links to EBU full Acol system files:
Bridge for All Foundation Level (Acol with a 12-14 1NT, 4 card majors and strong two openers)
Bridge for All Acol Level 2 (Acol with a 12-14 1NT, 4-card majors, 2♦ , 2♥ and 2♠ openings are either played as weak or strong)