Yup, you can cut and paste it, if one is provided (more and more they are). I use my own website to host my pics, and so I type in my url. However you get it there, with the img and /img tags, it should end up looking like the one in the example here.
I'm guessing that the most confusing part for alot of folks is the fact that you need to host your image on a server somewhere and then use the URL you get from that server to put in between the "img" and "/img" tags. Depending on where you host your image, the description of what the URL is can be less than obvious. You can always cut and paste that URL into a browser to see what shows up, or just use the Preview button on the posting screen until you get it right...
yea sending the info to the hosting site takes forever with my dial up, i usually have 3 or 4 things going when i'm trying to send pics over. it seems to take about 10 min per pic when i use photobucket, tinypic was the same. i like photobucket because they let you keep a photo gallery so once you get the pics on there you can go back and use them again without downloading again..
If you reduce the size of the pic before upload using some kind of photo editing software (if you have it), you can save a ton of time uploading. I reduce my 4 megapixel pictures to 25-33% size. They show up plenty large enough for viewing on the forums, and are only around 100-200K in size, compared to over 1 megabytes for the full-sized image.