Question
iam going to make my home next month in Boise, Idaho US.
i am planning for rose cultivation in pots.
kindly advise me as how to start with , where will i get the saplings , how to care those plants..
thanks in advance.

Answer
Here are the basic requirements to grow a rose in a container. The containers should be at least 18 inches in depth because roses don't like to have their roots crowded.
1) Choose large containers, with good drainage holes. Bigger containers means bigger and better roses!
2) Use a good commercial potting mix or blend your own rich but fast-draining potting soil. Avoid using large amounts of ordinary garden soil in pots, they pack down hard.
3) Water the roses often in hot weather, daily for small pots.
4) Feed them special slow release fertilizers and also liquid fertilizers as needed.
5) Store container roses in a protected spot, out of the winter winds but in an area where they can go dormant for the winter. Under large trees or a protected area on the patio is great. For areas that get winter temperatures below -15C for extended periods of time, bury the pots in the ground or take them into a greenhouse or storage shed for winter.
6) Each spring, remove the top 3 inches of soil from around the rose and replace it with a feeding of nice compost or well rotted manure blended with peatmoss or good garden soil. Sprinkle on a spring feeding of rose food at this time.
7) Do not over feed your roses in containers as a slow release such as Osmocote 14-14-14 will last all summer.
When you garden in a climate that gets  cold winter, your best best is your local garden center as they will only bring in roses that will survive the local weather conditions.
There is also mail order and here is a good rose nursery in Oregon that sends roses.
http://www.roguevalleyroses.com/home.php