hi yogesh;
there can be different reasons for choosing between assembler and compiler.if somebody is well familiar with "C" then it might be easier to start in that.also the availbiity of tools is the issue.if you want a free compiler check out sdcc compiler from links on left.but for a person without much experience in c it might be advisable to start in assembly.i can not recall exactly what MJK had quoted in one thread but it amounted to:first learn assembly and then go to C.
regards
Pranav