hoster sound setup

[ray ray]

here goes ? i have a hp pavillion notebook windows vista a Mackie 802-VLZ3 Ultra Compact 8-Channel Mixer vocopro dk3900 mixer amp a behringer usb interface
my ? is should i hook up sound from notebook to tape/ch in and out or should i hook sound from note book to channel 3/4 useing rca to 1/4 plug adapter and run sound from mixer thru main output useing rca to 1/4 plug

also how is the best way to hook up this system to record my daughter recording karaoke for pratice any help will be great as i have a big show this sat eve don't want to mess it up ups will be delerving the mixer today please help a tech dummy thanks raymond