Atmospherics

The CRB talks of creating atmosphere in your games, using pictures of landscapes and background music etc etc.
I can do the background music easy enough with the LOTR movies soundtracks, but I had thought about adding sounds effect too: weather sounds, animals sounds, footsteps, creaking doors, wolf howls etc etc. I could have these ready on my laptop to unleash at the click of a mouse.
Anyone else tried this?
If so where did you get your sounds effects from?
Any links would appreciated, preferably to free sites.
Cheers
Scott

If you just do a general search on google you should find sounds easy enough. Torrents are a good place to find things as well. Of course, the majority of items found with torrents tend to be illegal, but sometimes they aren't, I found an archive once, but wasn't using them, so I deleted it.