Babysitting is a tried and true way for any responsible teenager to make money (IF you like kids!). Any community that has families with small children needs baby-sitters. However, it is extremely hard to find trustworthy and reliable baby-sitters who are available on a regular basis.
Lawn or yard care
Another perrenial favorite. During the summer you mow lawns, trim hedges and so on. In the fall you rake leaves. In the winter you shovel snow.
Indoor house painting
You advertise your ability to paint individual rooms in a customer's house. Before undertaking this adventure you should make sure you know what you are doing by reading, working with someone with experience and practicing in your own home.
Baked goods (cookies, cakes etc.)
Many families are too busy to bake their own cookies and cakes these days. However, having fresh-baked goods around the house is nice. Also, a family might need a home-baked cake for a school bake sale or a party. You could provide baked goods for special occasions like these or sell baked goods at local craft or farmers' markets. Check local health laws as you are starting this sort of activity.
Cleaning
If you enjoy cleaning and do it well, then house cleaning for others is straightforward and easy. Find busy people in your neighborhood and clean for them once every week or two.
Pet Care
Most people who have pets want to give them the best care possible. Your business would help pet owners to do that by walking their pets daily or by providing in-home pet care when owners are on vacation.
Errand-running for busy people
Busy people often do not have time today to stand in line to get their license plates renewed, to buy groceries or to run other errands. Your business would handle these tasks for them.
Washing cars for neighbors
You can simply wash cars. There is also a whole industry called "car detailing". A detailer washes and waxes the outside and REALLY cleans the inside: vacuuming, washing the windows, armor-alling, etc.
Teaching older people how to use computers or the internet
Many older people are totally affraid of computers. If you understand computers you can help them. You could come to the customer's home (or they to your home) and you could charge on a half-hourly or hourly basis.
Using a computer application
learn Microsoft Word, Excel, PowerPoint, Access, etc. and then go get or create a part-time job in a small business using your skills
Creating Web Sites
If you are artistic and technically minded, there is a great opportunity available right now creating web sites for small businesses. Or try creating your own web site that generates a lot of traffic and make money selling ads on it.
Making and selling something unique:
A newsletter on something that interests you, something arty, etc. If you are artistic create greeting cards or draw portraits. You will discover that your greatest difficulty doing this is finding outlets, so work to solve that problem.
