In response to your question about what to send, my general feeling is that more is better.... As long as it's well organized so that your recommenders can reference what they like. In my packets, I included:
1) Stamped, addressed envelopes for each program requiring mailed letters
2) An overview of where letters need to go and when organized by medium (mail, online, email, etc.), a checklist-like spreadsheet, and a general overview of quotes from department websites about what they want to see in letters,
3) CV, SOP, writing samples
4) A letter on our professional experiences together to help them recall useful information that might be included in a letter (and as a sentimental thanks)
5) My UG and grad transcripts
6) Any papers I had written for them
7) A concise outline of other professional accomplishments
8) A card with a hand-written thank you note & Starbucks gift card
I also emailed a version of the packet with hyperlinks.
This is a lot of information, so it needs to be well organized to be useful... if you're not careful, your recommenders will get lost in a sea of information. A table of contents helps. My recommenders expressed real gratitude and said the packet really helped (one mentioned it in her letter! hehe).
All you really need, though: list of schools, CV, SOP, writing samples (finished or not)