^ Forget about the hill that you go up just starting out for now. Your legs aren't warmed up, so any incline won't feel good until you get the muscles warmed up and the blood pumping.
As for maintaining speed up other grades, here's what I do in the spring when I'm getting my legs in better shape after winter trainer sessions. I will designate a few of my weekly rides to concentrating on the long gradual grades that are on my commute route - I have about six or seven of them in my 14 mile ride.
So the first thing I do on those rides is try to back off my pace just a little bit on the flat parts - not go real easy, just down a notch from normal, to save my legs for working the rises. As I approach one of the upgrades I'll pick a spot - a mailbox or a roadsign - at the bottom and tell myself that whatever speed I'm going there, I will try to maintain that speed up the entire grade. With experience and time you'll find you will be at a speed that will be easy to maintain the first 1/3 of the grade, a bit harder the next third, then require some real concentration and effort to get that final 1/3.
Some days you'll make it, some days you won't. It works for me, and is pretty simple to incorporate into your regular riding.