Sanding

I'm finally working on sanding my podium.  I have some questions that I want to write down and research later:

• Do I need to sand all the previous paint away or just make it feel smooth?
• I think I want to paint it a burnt orangish color.  What kind of paint do I need if its going to stay outside?

I am using a hand sander that I already had.

I don't mind using this as my sander, but is

there something different I should be using?

Some helpful websites I learned from:

• http://www.diynetwork.com/painting/sanding-and-wood-preparation-before-staining/index.html
• http://www.ronhazelton.com/projects/how_to_sand_and_stain_wood_furniture
• http://www.ehow.com/how_6562804_paint-outdoor-wood-furniture.html