Good luck with the harp. I really hope for your sake it’s a good one. The Paki I bought (my first harp) had a real problem with levers that didn’t work and a cracking soundboard, so I had to stop playing it after only half a year because I was afraid it would break down completely. It had a nice voice, though.
I strongly recommend the Pamela Bruner books and DVD. She is very thorough in explaining everything, and you can always pause the DVD and practise a piece she just showed you. Also, she repeats time and time again what is the right hand position, which is really, really important to learn from the very beginning, or you may have to start all over again. I played for a year with a bad hand position, and when I finally got a teacher she told me I had to start again. So I bought Pamela Bruner’s Play the Harp Beautifully, and I am improving fast, with the correct hand position. So I absolutely think you should buy it, if you have to teach yourself.