Bricks, Masonry, Asphalt and Concrete - improving the look of my foundation

Right now I have a dull gray block foundation. I have my own stone on my land that i would like to cover the foundation with. What do I use to stick it to the block with and will last through all types of weather? What type of weather would it be best to do this project in...cold or hot?

warm dry weather is the best time to do this in, i would not reccomend sticking it to your exsisting foundation, unless you are using a product that is designed for that use(owens Corning makes overlay stone that is just a veneer and works very well for this application (about 6-10 dollers a square foot to buy)
to be able to do this with real natural stone you have two options
1. (Expensive) dig down to your footings and lay 4" block to the desired height of your stone membrane from block to foundation as flashing and that will carry your stone. lots of work but if you were redoing your whole house in stone or brick it is worth it.
2. (less expensive) Angle irons attached to the block at the desired height of the stone will also carry the stone, make sure especially with a block foundation that your bolts go all the way through the block and are bolted from the other side. the reason for this is that blocks are hollow and are rarely filled solid. bring a membrane either tar paper or an adhesive membrane from the wall to the tip of the angle iron for flashing.
I would think that probley the easiest way for you to spruce up the look of your foundation is to get somebody to parge it,

Most houses are parged and if done right last a very long time if you want you can colour the parging with mortar colours or even paint it if you want to, I would strongly suggest doing this and saving the stone for a fireplace or patio or retaining wall or something