A good anchor and windlass are high on the priority list. There's good information online for what type of anchor is recommended in Svalbard. Aboard Barba, I use 100 feet of 8-millimeter chain (I limit it to this length because of weight) and an additional 300 feet of 18-millimeter line. Since that trip to Svalbard, I have upgraded to a Lofrans windlass and a 20-kilogram Spade anchor. I also carry a 3.2-kilogram Fortress anchor that I can attach in series with the spade anchor. And I have acquired an anchor sail to keep the bow to the wind.
Undoubtedly the best guidebook for the area is The Norwegian Los, which is available for free online.
The best ports of call not mentioned in the guidebook were found by studying charts and paying close attention to the weather forecast for upcoming days.
To sail to Svalbard, you must apply for a permit with the governor, which is an affordable and straightforward process.
A satellite phone is an absolute necessity for downloading weather files and ice maps.
Condensation is a classic problem in the high latitudes. Insulate the mast with self-adhesive mats, use insulation under mattresses and along the hull, and be sure to have sufficient diesel on board to keep the boat heated.
Polar bears inhabit the entire archipelago and are often hungriest during summer. Follow the instructions from the Norwegian Polar Institute on this matter, and there will likely never be a tragic outcome for bear or human should an encounter occur. When traveling outside Longyearbyen limits, it's imperative to be armed with a powerful rifle in case of an encounter.
It is recommended that cruisers have experience sailing in polar areas before passing the northernmost point of Spitsbergen. First-time adventurers in these environs should consider sticking to the west coast.