First IPA

I'm planning on brewing my first IPA tomorow and was wondering if anyone could give me some good tips, anything will work. I' useing centennial hops whole flower. I was going to encorporate some pacific gems, but I'm not sure if this is a good idea? using victory gold barley, some second row, and oats.
hop scedual: 1oz cenennial @ 45 min; 1oz pacific gem @ 30; 1oz centennial @ 45 min; and 1oz centennial @ 30 min. this is a 4 gal batch, will i need more hops?

That's going to be one hoppy beast.

What exactly is your recipe?

4 oz of hops in a 4 gallon batch??? Man - YOU are a hophead! I like Cascades or Amarillo hops for IPAs. The Centennial is not a bad choice for bittering hops though.