I was testing by newly bought accelerometer for my personal project .I would like know what really the analogue values indicate? How could I calcualte the degree of Tilt or inclination using Accelerometers?

Google for the datasheet (.pdf)..
Tell which accelerometer.

Here is the procedure for using an accelerometer to measure tilt.

Simply put, measure the X (or Y) and Z acceleration and calculate

float tilt = (180./PI)*atan2(accX, accZ);

I am using an ADXL3xx series accelerometer then how can identify the axis can anyone explain with a diagram explaining the axes and the inclinations?

The data sheet will show you.

Thank you jremington