Q1. I have made 2 material and i want to save the material for life time. When ever i open in the material it should be saved in the material list and when i need i have to just click and use it. Is it possible if yes then how?
Q2. And where the file is store so that i can attach that file to my mail if the blender is corrupt i can again install that material file again.
The Blender default start-up file is named "startup.blend". On the version of Windows that I use for Blender, the file is located in a sub-folder of the users folder on the drive upon which Windows is attached named AppData\Roaming\Blender Foundation\Blender\VER\config, where VER is the Blender version number. I don't know enough about Blender on other platforms (MAC, Linux) to know exactly where the startup file is located there.
One way to do what you want is to start a clean instance of Blender, create your desired materials as data blocks assigned to the default cube, and then overwrite the default startup.blend file with the version you altered. Doing this will make the material library permanently available as part of the start up default. Note, though, that if there is a chance that you might want to use the original default file at some point, you may want to create the desired materials as a data block or data blocks of the default cube, and use the "Save startup file" option of the file menu (keyboard shortcut CTRL-U) to save a copy of the start-up file which would load instead. Doing this, will allow restoration of the default start-up file, by choosing "Load factory settings" on the file menu more easily than if you overwrite the startup file.
Instead of assigning the materials to the default cube, you can create your two materials ans click the F button next to the material's name (Save datablock even if it has no users) that will allow you to save your startup and keep your materials always available without assigning them to your cube.
Q.1 The best way currently is to keep it in the start scene and keep a copy of it. You can make a group of it so you can paste it in a new node material. If you edit inside the group it will change that group in all materials.
To save the current scene as start scene press Ctrl+U. To create groups select what you want to make a group and press Ctrl+G and select the Group Input node and press Tab to exit and select the group and press Tab to enter.
Q.2 You can use append and copy "things" from a .blend file like materials:
