Here's how I upload pictures. It may not be the best way but its the best one I've found & I have couple hundred pix in it.
To post pix I use photobucket.com & this is how I do it. First I have my pix in .jpg format. The .jpg is called a file extension that IDs that format from the many others. In transfer your pix from camera to computer you usually hav a choice, so go with .jpg. Then transfer them into your computer Pictures section.
Once into photobucket website, entered with your email ID, password, etc. Click on UPLOAD, then on Select Photos & Videos which will bring up something in your computer. Get into that and find your photo you want to upload and click on it. When it comes up look below it and type in a name to ID it. Then click on Save and Continue.
It then comes up in your Album. Put your pointer on your picture and a box comes up around your picture. At the bottom is a choice IMG CODE, at its right a box with [IMG}http etc etc. Click in that box and hold for a moment. It then is copied to you.
I then paste it on my notepad to keep it temporarily till I finish with my upload.
To post it in a forum you paste that in with your text.
After you get pix into photobucket, if you want to see them or download them again you click on Albums. Photobucket is free to begin with. If you get a lot of pictures in it, they will want you to become a member @ about $30 a year.