Once you have some photos online to work with, you can start editing them online. Click on the option labelled 'Your Photostream' on the Flickr home page. This will take you to a page displaying all your photos. Click the photo to edit and it will appear with a number of tool icons along the top. Select Edit Picture and a dialogue box will appear asking you to run the online image editor Picnik.

Click Yes and the image editor opens as a web page, with buttons to rotate, crop, resize and enhance the colours of your original photo. Hold the mouse pointer over each button and a panel pops up to tell you what each tool can be used for.

To adjust a poorly lit photograph, click the Exposure button; another panel appears explaining how to use the tool. Once you're happy with the changes, click OK - a dialogue box will appear asking you to give the image a descriptive name and to add a tag. We'll discuss the importance of tags later, but note that you can click the Cancel button while editing to return to your collection.

Once you're happy with the pictures, you can start sharing them by tagging them. This means adding keywords, known as tags, to images. A tag is a simple way to categorise photos. For example, if you add a photo of one of your children on holiday, you could add tags such as the child's name, the date ('Cornwall holiday', for example) and the year it was taken. On their own, the tags mean nothing, but as your online photo gallery grows, they'll become an easy way to sort your collection. Tags appear as clickable links in a list to the right of your images - click a link and every photo with the same tag appears in a new gallery.

You can add tags to photos as they're uploaded. To add a tag to a photo in your gallery, click it. On the right-hand side of the window that appears is a link labelled' Add a tag'; click it and type your tags in the box. You can add up to 75 per photo, but make sure there are spaces between the tags. To join two words together in a single tag, use double quotation marks to make sure the whole phrase is recognised - for example, "summer holiday". It is also advisable to put the most important keyword first, as this will appear at the top of the list oftags when the photo is viewed. Click Add to save the tags.