advice please!

I have been looking into getting hair extensions and this site seems to be a fountain of good advice and knowledge! I will try not to rant to much but basically about 6 weeks ago I had the worst hair experience ever!! I was asked if I minded a new person doing my hair, said no thats fine I went for my appointment at 1030am and was still there at 5pm I went from mid lenghth blonde to a so called bob with black and orange colour I only wanted my highlights doing!! they then offered to put some extensions in, they braided them in and I had to have them out 3 or 4 days later due to my scalp getting sores on them.  now $300 later in correction colour etc I still cant do anything with my hair so driving my partner mad he said he will help pay for my extenions, So what is the best method?   do you still need to go to hairdressers while they are in, Ive talked to a few salons and so.cap seems to be popular...and when they give you a price what are the extras you will need, like do you need special shampoo regular visits to the hairdressers while they are in etc....Im sorry for the long winded post, but I have just passed my esthetician course and dont want to go to interviews looking like this! thanks for any help and advice