For the first time you highlight or dye your hair, it is wise to get it done professionally. A good stylist will know which shade(s) of blond will look best for you. If the stylist uses permanent dye, the colour will stay in your hair until the hair grows out or is cut. You might want to discuss the difference between permanent and semi-permanent to find out which is best for you.
If you try "tipping" by your self and it doesn't turn out, you are going to have to get a professonal to "correct". So this is another reason to pay the extra money and get it done right the first time.
I would love to see pictures once you have gotten the tipping done.