There are basically two types of images most commonly used on websites - vector (line drawing) and photos. Vector art is most commonly used for logo design, usually have the extension of .gif and are limited to 256 colors. The other kind of image is a photograph. Photos are most commonly used to display products on a website. Because photos have many more colors in them the file size of photos are larger than those of vector drawings. For this reason you want to be sure to make your images no larger than what is necessary so that your web page will download quickly. Use a graphic software application like Adobe Photoshop to set your images at 72dpi because that is as high as your screen can interpret. Images for printing purposes are 300dpi. If you want to provide your customer with a high resolution image that they can print then zip the file, upload it to your server and add a hyperlink in your web page to the high resolution images. This is one way to make your web pages download faster. Remember, just because you have a high speed internet connection does not mean your customers do!
If you plan to create your own graphics you will more than likely want to use a graphic software application that allows you to edit the graphics. There are many to choose from but they can be quite expensive for the novice web designer. Software applications like Logo Design Studio Pro Vector can help you design logos inexpensively and can be purchased for immediate download for less than $30. But keep in mind this is not the best program for manipulating photos. Once you learn the basics of how a program like this works you will be ready to begin a more advanced software application like Adobe Photoshop. Adobe Photoshop is the most popular graphic software application used by Graphic Designers. It has many tools but will require time and patience to learn the program. The fastest way to learn Photoshop is by watching tutorial videos. Almost anyone can snap a photo with their smartphone but creating professional images for your website will require a graphic software program. Photoshop goes beyond adding filters like even the popular social media platform Instagram will let you do. Photoshop lets you add various graphics on different layers and then flatten it to make it become one photo. Photoshop also has an option to 'save for web' which will optimize your photo before placing it on your website. The graphic software package you choose will depend on your budget, the time you have available to learn the program and the level of professionalism you want your photos to have.
Please be aware that it is illegal to copy someone else's photo and add it to your website. Although Google images is a great place to start to get ideas for images you should not just copy these photos as if they were your own. If you are just getting started and want a few basic graphics for your website start with Clker.com. I use graphics from this website for personal websites and blogs. But for those creating professional /business websites I highly recommend registering at Graphic River. You can browse through their large library of images and purchase your desired image for a small fee. This is the most cost effective way to get images for your website. When you consider how long it will take you to create an image in Photoshop then you will soon realize it is well worth your time to just pay for images.
Which ever method you choose to get images for your website (create your own or purchase) - good luck and have fun!