Orion's list is a good start.
Here's the NH boating guide. It'll tell you what you legally have to carry:
http://www.boat-ed.com/nh/handbook/
Second anchor is a must if sand bars are in your future. I like the 2.2 kg Bruce-style claw as a second anchor. It's compact and holds very well. Put some chain on both of your anchor rodes too. Fortress makes a great primary anchor.
We carry a throw sack/rope. It's small and makes it easy to toss someone a line.
Some 30' dock lines can come in handy as spring lines.
Scrub brush is handy