As a private equity investor, what governance, information, and side-letter rights should I negotiate to protect my investment?

Your rights (and negotiating power) can vary quite a bit depending on how large your capital contribution is relative to the fund size. For example, $8M of a $10M fund will command much more power than $200k of a $10M fund. Smaller investors typically have little to no governance rights, outside of statutory rights. Larger investors can have a much more impactful role, such as a board or committee seat. Specifics of any particular fund will be spelled out in the governing and subscription documents, including what remedies are available. Although I’m usually on the fund side, assuming no conflicts, I’d be happy to review documents with you and point out things to review/look out for.