sand? prep? paint?

[barry 14]

hello everybody, over the winter i was looking to sand down my truck and do all the prep work in order to get it painted in the spring time. I have never done anyhting like this before and i was wondering if any of you guys had any helpful tips, or where to start, just anyhting to help. There's a couple spots of bubbling beneth the paint, at the bottom of the doors, along the rail around the roof, and hood. If i sand them down to bare metal will they be gone forver, or just come back? Also, i was wondering what you guys have done when the bottom of the doors and the hood began rusting? any comments would be appreciated, thanks.