In the old days of dial up modems and slow links the web did not have a lot of photos, and virtually no music or video. The links were just too slow to support that. Now a lot of people have high speed connections. Even if you are at a library or coffee shop the link to the Internet will be quite fast. But not everyone has a high speed link yet. And in places like coffee shops the links are not always lightning fast. But a lot of web developers have forgotten this. So they design very fat sites that download a lot of information. But this is the day of short attention spans. If a site does not load fast people leave it. So what can you do to speed things up?
Digital cameras now take photos that are anywhere between 8 and 24 megapixels. These are HUGE file sizes. That is a lot of data to download. Often people will put the photo into a website the same size it came out of the camera. Then they will use an HTML (web page language) command to tell the browser to display it really small. They think that now they have made the photo small. Well all they really did is tell the browser to zoom out on the photo, but the browser still needs to download the whole 12 megapixel file. So the page loads slowly. Even on the fastest of connections a 12 megapixel photo takes a bit of time to load. And if you have several of them it will be even slower.
What you want to do is to create a photo that is a much smaller file size. How you do this will vary depending on the software you use. So you might need to do a bit of a lookup in the manual or a quick google search for your software and how to resize a photo. I will give you a couple hints with some software I do use and know though. I have a Mac and use Aperture. This is a very nice program. If you like Adobe products then you should look at Lightroom (if you are on Windows that is your only choice of this style of program). Both Aperture and Lightroom are very similar. The programs record what you want to do on a photo to edit it. When you get all done and are ready to use it for something you then need to export the photo to a new file. This way you can create a lot of different photos really easily from the same base photo. You can create a number of different export profiles for the different uses you might have for a photo. If you create photos for websites then you want to create a particular export profile just for web photos. You will set the profile to export high quality jpg images (or png). The key is that you want to set the profile to output a photo where the longest side is no longer than like either 1024 pixels, or maybe 800 pixels. Most people view websites with a width of somewhere between 800 pixels and 1280 pixels wide. So the photo will be viewed basically at it's "native" size. So it will look really good on the web. You also take something that started maybe as a 4 megabyte file and reduced it to 130 kilobyte file. The smaller file is so much smaller that it will come down lightning fast!
Another thing you will probably want to do is put some sort of a watermark on the photo. This could be a mark that tells your website, or it could be your name. Anything that would identify the photo as yours. If you look at the photos on my site I always put the website on the photo. It is not a real watermark. By definition a watermark would go over the important parts of the photo (usually semi transparent) so that it will "mar" the photo. That makes it really difficult for someone else to use it. Mine is more of a logo or trademark. But it still marks the photo as mine and tells people I don't want others to use it and keep their mitts off.
Your profile in Aperture or Lightroom can also put that mark on the photo automagically when you do the export. Makes the process just one click (well maybe three click) easy. This is one of the many reasons I recommend Aperture and Lightroom to photographers as the primary software of choice. BTW, you can download a 30 day trial copy of either of those programs.
If you are using Photoshop or Photoshop Elements then you will need to open up the photo in the program, go to Image Resize, resize the image, and then save the photo as a new file name. You can tell Photoshop to link the two dimensions so that when you adjust one it will adjust the other proportionally. Not overly difficult, but not as easy as Lightroom or Aperture. And you will need to apply the watermark separate using either a custom made watermark brush or overlaying the watermark image by hand over the main image and then flattening.
You will be surprised how much more responsive your website will be, even on a fast link, if you resize all your photos before placing them on your website. Good shooting.