Block is a great - you will have a real fun time. There is nothing extremely crucial that you need other than an Eldridge Tide and pilot guide for LI Sound as well as good charts of the Sound out to Block Island. There is a good chart book I think from Map Tech that has the entire Sound including Block and I think up to Newport that is pretty affordable. The Eldridge will show you the tides and currents in the Sound and out through the Race. You will want to look at this so you time the currents right going out through the eastern end of the sound. They can get up to 4-5knts sometimes near the race and plum gut so you want to make sure you have them going with you and not against you.
Also not sure how familiar you are with the harbors and ports east of Sea Cliff but making the trip to Block Island in one straight shot is a bit of an undertaking so its best to enjoy it and break it into a few overnight stops in the Sound. That way also you can time your departures and arrivals for the day so you make the most out of the ebbing tide giving you a knot or more of extra speed and you won't be fighting it as if you made the trip in one shot.
Lastly when you get to the great salt pond in block you have your choice of staying at one of the three marinas, finding a mooring or staying on anchor. It's a pretty small island so its pretty easy to find numbers for the marinas and restaurants in the area. Also there are numerous books and online guides to read as well as tons of posts here on Sailnet about past trips there. If you do a search you can probably find tons of info. Let us know how it goes. I went for the first time 4 years ago and have been going ever since. I absolutely love it there.