Asbestos siding, if maintained, will last forever!
I'm not a house painter but, I would think that some special protection should be used to prep the shingles.
I would hire this job done by a pro. The paint job on asbestos, should last alot longer than on wood.
As far as selling the house, you will need to sign a form stating there is asbestos on the house before it is listed. Then, it's up to the buyer.
If the house is freshly painted, and the asbestos is in good shape, it will probably have little to no affect. Other factors such as where your house fits into the over all neighborhood will be more of a determining factor. You don't want the best house or the worst house when it comes time to sell.
As far as lead paint goes, this is probably more of a concern. Leads paint needs to be removed if there are going to be any kids in the house. (to protect your kids!)
Lead paint chips are believed to cause learning disorders and memory loss. (I grew up in a house that had lead paint, I think, I can't quite remember! sorry.)
Check with your town/city to see if there is any kind of lead abatement program there.
Again, this is another discloser that will have to be made. A young couple with kids, might walk away from it or ask you to pay for the abatement of the lead.