Your brother drives for Uber, your mother rents out your old room on Airbnb, your sister sells candles that smell like your grandma, and your grandma is running a quilting blog.

Almost 44 million Americans are reported as having a "side hustle."

Most people start them for one of two reasons.

One: they want to make more income.

Or two: they want to start carving a path out of their current job.

A side-hustle can definitely help you achieve these goals, but not without proper research and planning.

So here are five things you need to know to make sure that your side-hustle won't be hustling you.

[Two Cents]

Number one: do market research.

This is Jenny.

Jenny wants to quit her job and work for herself selling sweaters for hedgehogs.

After all, she's a member of the 20,000-strong Facebook group Hedgehogs 4 Lyfe.

If just 10 percent of those people bought a 30 USD sweater, that's 60,000 USD!

That's a nice dream, but before she starts knitting, it's time for a reality check.

Are there people out there who are currently making money at a venture like this?

According to one study, 85 percent of side-gig workers make less than 500 bucks a month.

AirBnB has the highest average profit of 924 USD a month.

Uber comes in 4th at 364 USD a month and Etsy, where Jenny's hedgehog sweaters will probably end up, is number seven at a measly 151 USD a month.

Maybe Jenny should sell a more established product—like supplements or makeup—with one of those network marketing companies.

After all, she's got Facebook friends who are always looking for new recruits.

If you're considering joining up with a network marketing company, be extra cautious.

According to a government study, only 1 percent of network marketing participants actually turn a profit.

By law, these companies have to share some of their financial data with you, like average income.

Before diving into any new venture, you should seek out every piece of information you can get your hands on that will give you some idea of how much you can realistically expect to make.

Number two: track your costs.

This is Tim.

Tim found out that the going price of used textbooks almost doubles around the beginning of the school year.

So, he figures if he sinks his savings of 8,000 USD into a metric ton of Intro to Biology, he can sell them on Amazon in September and double his money!

Not so fast, Tim.

Just because you're not making a product doesn't mean you won't have costs.

Tim will need somewhere to keep all those books for the next 6 months, which means renting a storage space.

Each book will have to be mailed to the buyer, which means 400 individual packing and shipping fee, and online retailers like Amazon take a cut of every sale you make.

Congratulations, Tim! You're still making a profit, but when you calculate how much time you're spending listing, selling, packaging, driving from the storage space to the post office, how much are you really making per hour?

Essentially, Tim is the sole investor in his own company, and no smart investor would put a single dollar into a new venture without seeing a honest list of expected costs and revenues.

If you want your side hustle to be a real business, you've got to treat it like one.

Which brings us to number three: use a separate bank account.

Kendra wanted to make some extra money so she started driving for Lyft on weekends.

After six months, she had more cash in her pocket and decided she liked it more than her day job.

But since all the costs and earnings were mixed up with her personal finances, she can't tell whether it's a good idea to go full-time.

If Kendra had started a separate bank account for her rideshare income, and paid for expenses like gas, maintenance and car insurance strictly from that account, she'd have a much clearer idea of how profitable her side-hustle really is.

You don't need anything fancy.

Just open a separate account in your individual name at the place you're currently banking.

It's a simple way to keep track of your new income, and will make your life way easier come tax time.

Speaking of which, number four: set aside taxes—now.

After a year, Kendra's made enough money to put a down payment on a new car.

There's just one problem.

This is the most consistently nasty surprise we see sneaking up on side-hustlers.

They've been making money from a new business but haven't put anything aside for when the government comes knocking.

We can't stress it enough: Do not make this painful mistake!

If it's your first year as a side-hustler and you don't know how much you'll have to pay in taxes, start by setting aside 25 percent of every dollar you earn for Uncle Sam.

[Consult a local accountant to find out how much you should be setting aside in your area!]

After your first year of business, you will be required to pay an estimate of your taxes on a quarterly basis.

Just go to this website to set up an online account directly with the IRS.

Believe it or not, they actually make it pretty easy to pay them.

Number five: jump with a parachute.

Jenny's hedgehog sweater company is really taking off thanks to an endorsement in Erinaceidae Aficionado.

But is it safe to quit her job at the widget factory?

Before she leaps out of that plane, she needs to make sure her parachute is big enough.

First off: Does your side-hustle profit equal at least half of what you make at your day job?

If Jenny makes 3,300 USD a month at Widgets, Inc. and her side-hustle is making a profit of 2,000 USD a month, she's probably in a safe position to give her two weeks notice.

Second: Does she have three months worth of expenses saved up for emergencies?

82 percent of small businesses fold because of cash flow problems.

And if the market for hedgehog sweaters temporarily dips, Jenny will need those funds to stay afloat until it goes back up again.

If that means she has to keep her day job for a little while longer… well, that's better than having to ask for it back!

This might seem like a lot of work and planning for something that was supposed to be "on the side," but it's essential that before you invest your time and money into a new venture, you understand what you're getting into.

It's not uncommon for people, once they find out what's actually involved in starting a side business, to decide they like their day job more.

That's why your side hustle should be something you genuinely like to do.

After all, extra money only has value if it's contributing to your overall happiness.

And that's our two cents!