Mentors can make your career. (Just ask Oprah.) The insights, tips, wisdom, and suggestions we get from people who have been there and done that will often take our efforts from barely scraping by to racing ahead at full speed.

I've had several great mentors in my life, including the late great Steve Jobs. More recently, I've worked with rock stars like Alan Weiss and Alan Cohen in my coaching and consulting businesses. Their time and insights have proven invaluable time and again.

And it's not just me. When you think about the most successful entrepreneurs in America, the cast of the TV show "Shark Tank" may come to mind. While these wildly successful entrepreneurs have largely succeeded by virtue of their own instincts and decisions, all had a mentor relationship that proved valuable at some point during their entrepreneurial journeys.

1. Barbara Corcoran: Never Underestimate the Power of Love

Corcoran's story is compelling: As the second oldest of 10 kids raised in a working-class town in New Jersey, she found ways to keep her siblings' spirits up by directing plays in their basement, drawing sidewalk games with chalk, and even setting up a store in the yard that sold rocks.

For as much of a power player as she turned out to be, Corcoran actually had no business mentor -- she says she learned everything she knows about leadership from her mother. She even wrote a book about it: "If You Don't Have Big Breasts, Put Ribbons on Your Pigtails & Other Lessons I Learned From My Mom."

In Corcoran's opinion, the best thing a leader can do is make sure that people are happy at work. If they're enjoying themselves, that's success to her. She didn't strive to be a leader; her goal was to be loved by the people who worked for her. Corcoran wanted to run a business in the same way her mother raised her family -- with lots of love and fun times. Seems like a good recipe, given the results.

2. Robert Herjavec: Think Big to Scale Big

Robert Herjavec owes much of his success to one conversation with his first mentor, Warren Avis, founder of Avis. It's the kind of advice every growing entrepreneur needs to hear.

One day, Avis (Herjavec's boss at the time) took him to the window and pointed at a hot dog vendor on the street. The successful entrepreneur told the up-and-comer: "You're the hot dog vendor. You're pushing your product, you're doing all the work, and you're sweating it to make a living. You need to be the guy supplying the dogs to all the vendors if you ever want to scale."

If you're an entrepreneur looking to grow beyond the grind, dig deep to find the opportunities to scale. Don't be the hot dog vendor.

3. Daymond John: Find Mentors Everywhere

Daymond John says his first mentor was highly unlikely -- a white, Jewish man from a relatively wealthy family. When this man married John's mother, he became a mentor as well as a stepfather.

John's stepfather taught him that people are people, and that it's important to be proud of being an African-American man without despising what others are. While this lesson doesn't directly correlate with growing a business, it's one that undeniably shaped John's life and character, and thus his professional success.

Mentors are everywhere. Be open to the lessons life has for you, no matter where they come from.

4. Mark Cuban: Learn What Not To Do

My favorite might be Mark Cuban's story of a "reverse mentor."

When he first started out, Cuban was charged with opening up the software store where he was working. However, he had a big deal he wanted to close for the company, so he recruited someone else to cover his shift so that he could close a $10,000 deal for the store.

When he came back to the store with the check, his boss didn't praise him; he fired him -- ostensibly for not dressing well enough and wearing cheap suits. This taught Cuban that caring more about how things look on the outside than sales and revenue is a death wish for business owners.

Cuban knew from that day onward that he wanted to focus on the metrics that truly matter to a company -- not insignificant details that don't affect the bottom line.

There are plenty of examples of how to run a business out there. Look around and figure out what you want to replicate and what you want to avoid. Like the successful entrepreneurs of "Shark Tank," who credit their success to mentors, your first goal as an entrepreneur should be to find solid, experienced mentors who have your back. There's no telling when they'll hand you that golden nugget that skyrockets you to success.