sure that computer sounds like a good spec
u can get a great guide on the whole process from here
http://www.dvdripguides.com/prod01.htm
it lists what software u need and exactly how to use it
it has links to the software as well,
its very easy to rip a PAL dvd rather than a region one NTSC release as they require a bit more work
hope this helps
time wise for your spec of machine and depending upon how fast your dvd rom drive is, should be around the 8 - 10 hour mark for compression, could be faster although its very dependant upon how big the dvd files are
most of them will take up around 4-6gigs of space when they are ripped to your hard drive