I used the coax off my VCR for the video and then fed the audio from the VCR into the line in. There was less noise in the audio. The Svideo is of higher quality so you'll want to use that. The folks at dvdrhelp.com can point you in the right direction for what software to use. If it helps I recorded with Dscaler then used Tempenc to encode it to vcd format.
To grab tose analog signals Dazzle makes a decent USB device called the Dazzle Fusion that will take analog sigs and convert them to avi's on your computer. Also has a nice little software package for amateur video editing. I picked one up at Sams club for like $70.