For daily practice if you work or study, 30 min are quite enough ... and don't be frustrated if you can't play like malmsteen, cuz you won't be capable of doing so if you've just started out.
To be able to play Malmsteen's stuff, you'll need have at least a couple of years of guitar playing experience , may be less may be more.. It depends on you mostly.
[Edited by SLY on 01-13-2003 at 09:27 AM]