I did some cleaning in my garage this weekend and realized I had left some motor parts exposed to the elements throughout the winter and they had some rust build up. I was just wondering how much harm does this do to the parts? I plan on removing the rust but what would be the best way to do that without affecting the parts? Thanx ahead of time with any suggestions. Oh, also what would be the best way to preserve them so this doesnt happen again?

What parts are we talking about and where is the rust?

Most of the rust is on my cam, but nothing severe. Then I also have an intake and a pair heads with some rust on them.

For any mating surfaces and especially on the cam use a rag and brake cleaner. Should remove most if not all light surface rust. For any non mating surfaces or anything not critical use steel wool and hope there is no pitting in anything.

I wouldn't trust a cam with any significant amount of rust on it. Throw it in the trash and get a new one. The lifters too, unless they're rollers, and have no rust.

Intake and heads don't too much matter.

The quarter car wash does a surprising job of getting light surface rust off of castings, tin, and accessories.

Paint them afterwasrds; maybe with some POR-15 or similar before the regular engine enamel.

You can spray a camshaft with WD40, then wrap it up in a garbage bag for storage.
I'd use some green scotchbrite on just about all of those items. Just scrub them. Or for hard to reach areas, get some naval jelly or "rust dissolving" liquid and just spray it on and rinse it off. Spray paint the heads/intake, except for mating surfaces.

Any rust at all on a cam is severe.