Playing against f4 Sicilians

Hey Guys,
I play usually my Dragon,
But i see a lot of f4 or Nc3 f4 sicilians,and do not tŕeally know how to play against it..

@the_loving_boy #1
Early 1.e4 c5 2.f4 is considered slightly unsound because of 2...d7d5 and the Tal Gambit
en.wikipedia.org/wiki/Sicilian_Defence#Grand_Prix_Attack:_2.f4

However, afaik GM Sveshnikov has helped to develop the system with 1.e4 c5 2.Nc3 and only then f2f4, which is a big improvement for white.
See here the Grand Prix articles to get an idea.
http://www.kenilworthchessclub.org/articles/index.html