Having finished my own doctoral work not to long ago, here are my low and high tech tips:

Low Tech: (books)
1. The Now Habit (to fight procrastination)
2. On Writing Well (William Zinsser)
3. Elements of Style (E.B. White and Strunk)
4. Manual of Style (Turabian)

High Tech:
1. OmniOutliner
2. Scrivener (for organizing notes and the first draft)
3. Word (subsequent drafts-plus odds are your advisor will be using it and want to add comments)
(Laptop - assuming you don't have one. I couldn't imagine writing my disseration without the abililty to consume large amounts of coffee at the local coffee shop or bookstore. Also, I found it really helpful to write in different locations, just for a change of pace)

Good luck in grad school.