painting over finish?

[renai.livejournal.com]

I have a varnished/finished desk that I'm planning on painting tomorrow. The desk has obviously been sealed, but I'm not so sure that you could really call it varnished. Anyways... I don't have access to a sander, so what are my options for being able to paint over it? I was thinking that if I just used primer under the paint I would be fine, but I'm not sure.

Also, a pink desk with alternating black and white drawers: cute, or completely obnoxious? I'm moving into a new apartment in a week and I'm afraid that I may go into shock from lack of color, so I'm trying to spruce up my furniture a bit.

Any advice is appreciated!