I have my higher maths exam coming up in a couple of weeks and one of the things I just cant get my head wrapped around is completing the square. I am looking for someone to take the time and show me how to do it as clearly as possible. Just in case anyone isn't entirely sure on what it is, it is something along the lines of:

Express x2+3x+5 in the form (x+a)2+b


Thanks in advance for any help I recieve.