The word partnership covers very different arrangements. Before discussing terms, decide what you want to change and how involved you want to remain in the business.
Separate the need from the structure
If you need someone to run marketing, selling equity may not be necessary. If you want to step away from ownership, an advisory engagement will not solve that. Start with the outcome you want.
Ask who will do the work
Understand who is responsible, what they will deliver, and how decisions will be made. Discuss access to information, reporting, and what happens when the plan needs to change.
Review the terms carefully
Fees, ownership, decision rights, and exit provisions affect the relationship. Take legal and financial advice appropriate to the arrangement. A useful partner should be comfortable with clear written responsibilities.