I use two navigation triangles. I find them more convenient than a parallel rule or the rolling rule. The parallel rules with the protractor attached are from the aviation industry originally.
A number two pencil seems to work the best. Erasability is more of a factor than fineness of point. get a box of 'em. Save the short nub of the oldest one. It is a navigational fact, you can probably look it up in Bowditch, that a brand new, freshly sharpened pencil will not last for eight hours on any size vessel. The entire crew of said vessel can be interrogated at length and your new pencil will not show up. That is, until you reach port, at which time you'll be rolling in them. On the other hand, a two inch pencil stub will survive collisions, typhoons, and myriad other catastrophes untouched. Tie it or tape it near your navigation station or chart table and rest easy, secure in the knowledge you will always have a pencil. This information is not warranteed for pencils of greater length than two inches.
You may find that you use the same chart, and courses, repeatedly. Once you have established the course you wish to use for a particular voyage, you can ink it in. Wait until you are sure that is the one you want to lay down permanently. Don't ink it if you do not have the Scotch tape that you can write on with the pencil. Place the scotch tape over the inked course. This will allow you to plot positions with pencil, easily erase them, and protect the chart and the inked in course. do not use red ink.
As the Dog mentioned on dividers. Try them out before purchase. Everybody is a bit different. I do not care for the bow dividers but do like ones with long arms. They should be comfortable for one handed operation and be easily controllable that way. Keep their points sharp, using only the lightest pressure on the chart, so as to not punch a hole in the chart. A divider hole in a chart can turn the most taciturn navigator into a thoroughly po'd shipmate.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.