I've owned LOTS of cheap bicycles so I guess you don't have to be too embarassed. But, looking at that stem, bars and brake levers just makes me want to hurl. I can just tell by looking at it, it probably doesn't "feel right" when you ride it. Anyway...
For a cheap bicycle like that, I might go with Promax brakes (requires noodles):
http://www.niagaracycle.com/product_...ucts_id=433557
If you wanted to upgrade that, I'd go with dual compound Kool Stop brake pads.
You know, I was researching tires lately and found the grip on the Ritchey Premonition very cool. You can check it out here:
http://www.chainreactioncycles.com/M...?ModelID=53814
You may also want to check out a saddle (WTB Freedom Greenbelt), it's currently on sale:
http://www.niagaracycle.com/product_...ucts_id=705470
EDIT: I just have to add brake levers to that list. The following is actually a left and right brake lever, not a pair so you have to order both
http://www.amazon.com/Shimano-Altus-...292774&sr=1-52
and by the way, for V-brakes, you can use them front or rear (same model for both)