basic vlan questions

I have some voip phones and someone suggested that I would be better off if i put them on a vlan

1) would putting my voip phones on a vlan help with data loss? or bad connections?

2) how would one set this up on an asg 120? running utm 9 or is this done at the switch? (i have two 24 port dumb switches)

3) would it be more affective to dump all the phones on one switch and all my pc's and wifi onto switch 2 and run them both directly into the asg 120

3a) how would i setup the interfaces?



Sorry this is kinda of a broad topic but im pretty weak on my networking knowlege


Thanks