Without going into much detail, a good way to learn of the whole process is to visit many dental school websites. They usually can help build a good foundation of the process involved during application. Once you've done that, then ask questions on this forum to fill the gaps (Do a search first to see if the topic has been discussed in the past). I'd say the order of importance is as follows:
1) GPA
2) DAT
3) Experience in Dental field
4) Volunteering
5) LOR's
6) Personal Statement