Determine business goals and participants.
It is always smart to begin a project with the end goal in mind. Decide who from your internal team needs to participate, and who should administrate the environment. Identify your partner participants, as well.
Create an external network.
This step can be completed with either the paid or free versions of Yammer, however, my recommendation is that any site built for the purpose of collaborating with partners should be created using the paid version, which comes with administrative controls not available in the free version. To create the network, on the bottom left of the Yammer interface select Networks, and Create a New Network. Select External Network, attach your logo, give it a name and a description, and make it an Open network (any member can invite new members) or a Closed network (only admins can invite), and determine whether others within your company can join without an invite (if selected, people within your company can browse external networks and join without an invitation).
Establish guidelines and standards.
As part of your initial planning, hopefully you took the time to outline how members would use the network. Add to that planning any corporate governance policies and procedures that may be relevant to the sharing of sensitive information, or the proper use of member contact information, and create a Note or attach a document that outlines these guidelines and standards. My recommendation is to create a network Frequently Asked Questions (FAQ) document, pinning it along with any other supporting documentation to the right side of the interface where all participants can easily find them. Another strategy is to add your guidelines to an Announcement, and require all members to acknowledge viewing/reading them before allowing them to participate on the site.
Seed the conversation (both public and private).
No matter how collaborative you are within your organization and with your partners, even the most social teams need prompting from time to time. Staying true to your network purpose and goals, regularly reach out to members for feedback, and share relevant content and conversations with members using the Share feature.
Don’t let a question or comment go unanswered.
Beyond seeding the conversation, making sure every question is answered and comment viewed is a critical aspect of any successful social environment. Even though members may check in on the network several times a day, messages can be missed and participants can become discouraged – negatively impacting the value of the network. One strategy I often employ is to redirect comments to the appropriate people using the Share feature, or by simply replying to the comment by adding the names of the right people in a reply. This alerts your members that a comment or question is waiting, and ensures that the dialog keeps moving forward.