Well, i walked the web for a while now and finally i had to make a checklist myself of designing Active Directory. I hope this super simple guide helps presales, consultants and other enthusiasts out there..
10 Hot-checklist for Implementing/Designing Active Directory:
NOTE: Please know AD first then by running this checklist, you can't go too wrong.
1. Organization needs for AD
2. Forests and domain structures
3. Domain Name System, WINS and DHCP
4. Sites and Replication
5. Domain controllers, FSMO, GC
6. Organizational Units
7. Group Policy
8. Users, computers, groups and objects naming
9. Security (authentication, auditing, authorization, etc)
10. Schema extension, custom coding and application integration
Of course there are a little more things one must consider when designing AD but here's a good start to working on another list.
Hope this helps :)