Photo wise, if you look at the icons above your post, you'll see a little picture next to the youtube icon, not too dissimilar to your plot. Any picture on the web when you read another website has a url that starts with http:// blah blah. You can get this via right clicking on it, pressing properties, and copying the url. Then press the pic above, paste the url inside, and press insert image. This gives you the tags that the website needs in order to display a picture.
Tags look like this [img]your url goes here[/img] You can write the tags either side of the url if you want to, but simply by copying the image code from Photobucket and pasting it straight into your post will do the same job.
For youtube videos, you can normally copy the url from the top of the page and the forum will do the rest. Occasionally they play up, but normally work.
If you have any specific questions, start a thread in the forum section, where anbybody logged on will see it and no doubt help. This will encourage others too. We all need a little help at times, so go for it.
Also, I put a 'Help' page which you will see if you hover your mouse cursor over the Profile tab. There is lots of good help there too.