do llanowar elves have summoning sickness for forest
do llanowar elves have summoning sickness for forest
I get the distinct feeling that you're confusing lands and mana here. Remember:
Lands are not mana; Mana is not land.
Llanowar Elves does not produce "forest" -- it produces green mana, which is the same thing that Forests make when they're tapped for mana. When you use the Elves's ability, you simply add one green mana to your mana pool. It does not allow you to grab a Forest from your library -- that's what a card like Evolving Wilds or Misty Rainforest is for.
So, to answer your question:
Llanowar Elves, being a creature, is indeed affected by summoning sickness. This means it cannot activate its mana ability the turn that it enters the battlefield; you must wait until you've controlled it continously since the start of your most recent turn.