Making money out of photography is not easy especially if you want to do it as hobby and with a limited amount of effort. Professional photographers make their money from wedding, portrait and corporate photography but they need to stand out in their field and produce amazing results. Some may be able to sell their creative or landscape photography as art but again need to offer something wow, different and creative and also provide opportunities to sell them, e.g. online, shop, market stalls.
You could consider selling your photos through stock sites. Stock sites are used by people who need a photograph for commercial, editorial, entertainment or artistic purposes. For example, a holiday company may need an image of a destination they are advertising on their website, a newspaper may need an image of an animal it is writing an article on. Rather than take the photo themselves they buy one from a stock photo company.
This may seem a great way to make money however there are a few issues. Firstly, there are huge amounts of photos available on these sites. You may have a great photograph of Whitby but there will be 1000's of others similar on there too. Secondly, the amount of money you get if you do sell one is very small (often pence rather than pounds). The amount changes as the companies buy a licence to use your image and it depends on the size of the audience on how much they pay.
However, it is possible to sell on there sometimes and once they are uploaded then there is nothing else to do so you can just sit back and see what happens. To increase your chances you should:
Make sure you follow the instructions and advice on the stock site regarding giving titles and tagging your images. This will make your image more discoverable (Hint: if it is an animal put the Latin name too).
Avoid taking the same images you see of somewhere. Try to find a different angle.
Remember people don't always want a photo of something amazing they might just want a photo of a hand, or a book, or a cup of tea. These are the images that there will be less of.
Put on as many as possible to increase your chances.
Below are some stock sites where you could sell your photos. They have different rates, some you have to apply for by sending some photos before they will let you join and they have different acceptance policies. One image may get accepted from one site but rejected by another.
A new opportunity on the market is Picfair. This is different as it allows you to sell images for art work. You set a price and then people buy from the site. The site takes care of printing, mounting etc. It allows you to set up your own store which you share with people.
You could also look at Etsy. Etsy is an online buyer and seller community similar to eBay, except it focuses on hand-crafted or vintage goods. Most products sold fall into the category of arts, crafts, jewelry, paper goods, and housewares. Many photographers sell digitally downloadable images, or you can sell a mounted signed print. It's entirely your choice.
As I said at the start, it is not easy but it may be worth a go and give you a little bit of money for your next piece of camera kit!