Re: Marblehead to Hampton, NH
talbot gave you good advice. The few things that I would add are:
If you haven't done a lot of bridges, try to arrive at the entrance to the Blynman canal close to slack water, at maximum flow, you probably can't motor against it. From time to time, a sailboat will get a shroud hung up on the bridge so just make sure that you have lined up well to the bridge. They try to open for a minimum amount of time so get close, call the bridge on 13 and then be ready to hit it through there. The outgoing traffic always has right of way.
The train bridge is pretty easy, just be sure to hug the east side as you can get your rig hung up if you are too far west (the span swings 1 way so there is very little clearance on 1 side). If you are waiting for the bridge (they area also on 13), don't stray too far west once you get past the marina as it is really shallow. Be aware that the MBTA plans to replace the train bridge and the work was originally supposed to start in May but there doesn't seem to be any updates coming from anyone so I doubt that it will be a problem. Their plan is to keep the train part open but it is unclear as to whether the bridge will be capable of opening to let sailboats pass. The rest of the trip is relatively straightforward provided that you follow the channel. In mid summer it is a zoo but before July, it is nice.
Going out and around Cape Ann is really easy and fun although there tends to be very little wind and a decent amount of current off of halibut point. Don't go inside milk island and think twice before going inside Thatchers. Another common problem is people getting too close to the Londoner off of Thatchers. Finally, if you haven't been to Rockport, be aware that the breakwater was never finished and so a large portion of it is just below the water's surface.
If you just need to get this done, then a single day with reasonable winds that are not from the N, NE or E should be fine. If you go through the canal, there are not many places to anchor if you decide not to complete the trip. Your best bet would be to call the Annisquam yacht club and see if they have a mooring for you. If you go out and around, it would be a longer day or you could stay at Rockport. Rockport inner harbor is pretty protected but if you anchor off the beach, it can be rolly and you don't want to be there in big swells or any form of N or E wind.