nekko :
...if I then get a 3.5 mm to RCA (Red & White for sound) and hook it up to the 3.5 mm on my mobo then I should be able to then get sound from my computer to my tv right?
Yes it will work, but you might end up with slight audio synch problems, but it's a hit/miss issue with that, and likely not terrible if even noticeable.
And also will the picture coming from the s-video to component be as good as normal component, dvi, or hdmi?
It's not S-Video it's a 7-8 pin HD Jack that caries the SV and Component information through the same connection, but it's Component out, or as you call it 'normal component' out.
Anywhoo, it won't likely be as good as a DVI or HDMI connection, only because of the nature of the singaling (D-A-A-D), but it might also be 99.44% as good depending on how well your TV handles the signal provided (where it's 1080i or 720P, etc).
DVI and HDMI have the advantage of being less susceptible to corruption and also being better handled by most HDTVs due to the digital nature and easier mapping. If you know what you're doing you can make both look close to similar with a little or a lot of work depending on the help from the Graphics card MFR and drivers/apps.
DB-15/VGA or DVI or HDMI are usually just easier to setup and get working, and on some TVs you are just limited by your inputs and how the TV handles them.