Saving money is important, but it's kind of hard to do when you haven't made any. School, sports and other extracurricular activities can leave little time for a steady job, so here are 10 ways to earn some extra cash in your free time.

• Stock Photos. With an eye for photography and a decent camera, you can sell stock photos on websites like shutterpoint.com.
• Yard Work. Aside from the standard lawn mowing and weed pulling, consider offering seasonal services. Try pruning trees in the spring, or shoveling snow in the winter. You might also find work putting up and taking down holiday decorations.
• Babysitting. Get a few gigs a month for a couple of families. Or, hold a "parents evening out" for multiple families and watch all the kids at once. If they're a handful, ask a friend to help and split the money.
• Reselling Books. Check garage sales and libraries for deals on used books. By choosing carefully, you may be able to re-sell these online for a profit.
• Green Thumb. Grow simple herb gardens or flowers and sell them at local farmers markets on the weekend. You'll be surprised what people will pay for seeds, dirt, water and patience.
• Event Staff. Check with catering companies in the busy summer wedding season. Also check with event-planning companies year-round to see if any help is needed.
• Cleaning. Offer to clean houses, garages, gutters or vehicles. Do a thorough job and you may get a few referrals.
• House-sitting. People leaving town may need their plants watered, pets fed and mail collected. Start with friends and family to build a positive reputation before branching out.
• Computer Lessons. Teach simple computer skills to seniors, or offer to do computer-related chores. You can scan photos, help shop online, import music onto their computer or set up an MP3 player. Simple tasks like these are greatly appreciated.
• Surveys. Complete surveys from websites like surveyspot.com. Read their privacy policies before giving away any personal information, and make sure they're legit by checking them out on bbb.org.

Sources:

washingtonpost.com; ehow.com; about.com; surveyspot.com; shutterpoint.com; bbb.org; computertutorforseniors.com; moneycentral.msn.com; auctionbytes.com