Hi there abelmiah! Welcome to Elysiun!
Very good for your first post - don’t worry, everyone has to start somewhere!
To address some of the problems that you stated yourself:
Am I right in thinking that your spotlight has buffer shadow activated? If that’s right, increase the samples value in the lamp’s settings to reduce the jagged edges.
Try turning down your specular values on the materials of the objects - they’re overexposed so it’s difficult to see what’s actually happening. I’d also suggest turning down the lamps a bit - especially the spotlight - too bright! 8)
Try turning on Ambient Occlusion in the World Settings - it fakes global illumination. It’s a very good way of making sure lighting is even, and also improves the look of your model drastically! If you find it looks ‘dirty’ increase the samples value under Ambient Occlusion (this will slow renders).
The speakers could do with a bit of smoothing. Select the faces you want smoothed and press ‘Set Smooth’ under the Edit Buttons. You will probably find that you end up with horrible black marks when you do this, so press Ctrl-N in Edit Mode to recalculate normals.
Alternatively, enable ‘Subsurf’ under the Modifiers tab. This will turn your speakers VERY rounded! However, selecting individual edges and pressing Shift-E, then increasing the ‘Crease’ value to 1 will crease those edges.
Hope these points help, and that I haven’t just overloaded you!
You’ll find many tutorials at http://mediawiki.blender.org, as well as links to external tutes.
EDIT: I’ve just realised, I think you should make the desk structure more strong - those legs will snap like twigs!