Hi. Sometimes for my projects i use some free legal sound effects.If u need sound effects too,i share with u :
http://www.lucidsamples.com/free-sample-packs/181-free-sound-effects-sfx-pack.html
http://www.audiomicro.com/free-sound-effects/free-electronics
They are really not bad and free.If u know good free legal sound effects, pls share with me.