Here is a straightforward look at this topic for Malachain.
Founders often look for advice only when something has already gone wrong. A mentor met early can help avoid those situations by pointing out blind spots in pricing, hiring or contracts while changes are still cheap. Good mentors are usually people who have run a similar business a few years ahead of you, not necessarily the most famous names in the field.
Volunteer mentoring organisations, local chambers of commerce and industry associations are practical places to start. Arrive at the first meeting with a short summary of the business and two specific questions. Respect their time, report back on what you tried, and the relationship will grow naturally. Over the years, consider offering the same help to someone newer.
The most useful step is usually the first one. Pick a single suggestion, try it for a couple of weeks, and then decide whether it is worth keeping. Small, steady improvements last longer than ambitious plans that are hard to maintain once everyday life gets busy again.
It also helps to talk the subject through with friends or colleagues who have tried something similar. Their experience points out the details that guides leave out: how long things really take, which costs were unexpected, and which shortcuts turned out to be a mistake.
There is more to learn on this subject, and the linked website goes into greater depth. Treat this article as an introduction rather than the final word, and check any important decision against up-to-date, reliable sources before relying on it.