Fair question. First, we've created both a guide for equity to give and a template agreement (w/orrick and gunderson) that can be found here members.founderdating.com/resources/templates
Second, for any advisor you start working with you should be cognizant of what they are bringing to the table. In my mind their value can come in a couple categories:
1. Industry Knowledge - they are an industry expert. Often times these aren't startup people, but people inside an industry that understand it and can help navigate it.
2. Product Knowledge - they are great at a certain area you need help in - mobile distribution, hardware manufacturing, B2B sales, technology scaling, etc.
3. Relationships - they are a connector and not only can they get you to people (this can include fundraising) that you need to talk to but they are willing to - important distinction.
4. Entrepreneurial Leadership/Coaching - they've been through the entrepreneurial trenches and they can help you with big and small decisions. They've built teams, they've failed, etc. Don't underestimate the importance of this last category.
You should verbally agree to a time commitment with your advisors and how they want to communicate in between e.g. once a week by skype or every 3 weeks in person. You can put it in an agreement but at the end of the day if they don't want to engage an agreement won't force them.