Do you love dogs? If you do you can try to offer dog walking services or pet sitting.
Go look around, for wild flowers, pick them up for free, make a bouquet. Wrap the bouquet with a flowe cellophane wrap, that has a ball at the bottom for a little water to keep them fresh. Go to grocery stores and ask them if they can display the flowers for you and split the profit. Go to night club and offer the club visitors to buy flower for his girlfriend. Sometimes I see people on the side of the busy road, selling flowers, another place you can sell. Sell the bouquet about $5 to $10. If you can't do a bouquet, get a lady friend, and do a partnership. Who knows it might turn to a real business.
Another idea I have is to do online surveys. You need to do many surveys to make a substantial income, from many different survey sites, but right now I only know one site
http://www.ciao-surveys-international.com/
If you are good with search engine you can try helping people find answers on the net and get paid for it.
https://www.chacha.com/
http://www.mylot.com/
Well I don't have anymore simple way to make money. Other ways is to become affiliate marketer, basically you have to know internet marketing and is not easy. If you are good marketer you can make a lot of money. Here is a rough draft about this business. Sign up at http://www.clickbank.com as an affiliate, which is free. Find a product you wish to promote, from clickbank market place. Once you find the product you want to promote, get an affiliate link. After you get the link, to promote for free, write an article about the product in ezine articles, or goarticles, and put your affiliate link in your article. If you managed to find a specific niche, and not many people are doing it, your article will be listed in the first page by Google in two days to 2 weeks. By a specific niche means that when you type a word a search engine not many people are searching for it. For example the search term dog, can generate many google result. However, the word Dog training, will generate fewer result then the word Dog, by itself. This is the kind of search term that you want to focus, with a very specific term. To go further you can use the words Dog Training for Jack Russel Terrier. This is a very specific term, and maybe only a few thousand results, and this is what you want, so your articles will be on Google first page, and hopefully they read your article and buy a book on dog training. Kind of complicated, but that's what you have to learn.
Sometimes you can try to contact the publisher of the book that you want to promote his product, and 90% of the time he will give it to you for free, so you can write a better article about it.
Good Luck