Webb (pictured), who has Football League experience with Southend United, Brighton, Hull City, Yeovil and Lincoln City, joins the Dons after a brief spell playing for Maltese champions Marsaxlokk.
Brown said: "Dan played against Aldershot Town when he was on loan at Woking last year. He ran us ragged, as well as scoring a good goal, and I made my mind up at the time that I would sign him if I could. Now I have, although it is for another club!
"To be honest, I thought I'd lost him because when we heard he was available earlier in the summer we made him an offer but instead he went to play in Malta. But when he became available again, we snapped him up.
"Dan is young, he is only 24, over 6` 1" and plays as a genuine target man. But he is also mobile with good touch, so we won't be worried about playing the ball into his feet."
Webb said of his signing for the Dons: "I was tempted when Terry made me that offer but I had already committed to Malta and felt I should honour that commitment. But it didn't work out and so I am delighted that a big team like AFC Wimbledon has come in for me."