the best way you can prepare for interviews:

1. gather information about the question they  possibly ask.

2. increase self confidence.

3. talk to someone who has attended the interviews 

4. be prepared before the final day

 to prepare for general awareness:

1. read!read!read!
if your can read newspaper then just go for it.

2. try to spend at least 1 hr in gaining knowledge regarding the same everyday.

3.internet can be a uselful source too for gaining general awareness