You need to start developing a system of mentors as early as possible. One of mine was a professor of mine when I was still in junior college. I’d stay after class to talk to him, and through these conversations I discovered that he’d just completed the MPA program at Georgia College and was teaching at GMC until he started working on his PhD (sound familiar?). We fell out of touch for a few years, then reconnected when he came back to GCSU to visit when I had transfered there. Will (see picture below), in addition to my undergrad advisor and my thesis chair, have walked me through seemingly insurmountable research questions and tasks. I’ve asked their advice on everything, from research methods and suggested topics for papers to advice during the eventual job search.
Do not neglect attending conferences at every possible opportunity. This is how you meet contacts in your field of study. There will always be someone there with whom you have something in common beyond academics. For example, some of my friends I’ve met through conferences I actually started talking to concerning the music at the conference dinner. We swapped contact information, and stayed in touch afterwards. Contacts like this can, like your cohort, take a look at drafts, provide advice on topics to research, and sometimes (if you’re lucky) coauthor papers with you. With today’s technology, this collaboration is more easy than ever. Cloud computing allows two (or more) individuals to edit the same document, and see changes in real time. Some of them even allow a separate chat window on the same screen so you can discuss changes as they are made.
Finally, don’t forget that, if everything works well, you are “stuck” with these friends throughout your program. Make sure you do some fun things together too, and not just always academic. Some of the most memorable times I have were when we’d just stop working for a couple of hours and everyone would walk the few blocks to downtown and go to The Brick. Or, when things were too hectic for that, order some pizza and everyone get together in the conference room. Those are the times that make grad school something you’ll never forget.