1) IMAGES
You should re-size your image in Photoshop to something like 400 x 600 pixels before you post it, so that you download the image quickly and you save space in your file quota.  For your audience to be able to see an enlarged image, you need to either link to the original image file by clicking “File URL” or by choosing a larger Size, then hit “Insert into Post”.

You MUST cite any picture that you don’t own:  say what is the subject and what is the source.  In order not to compete with the original, it’s best if you post an image that is much smaller than the original and link it to its source if you can.  [Worst practice would be to scan something from a book and post a big image online: it violates copyright law because it discourages purchase of the book.]

2) LINKS
Make your weblinks active: highlight a word and then click the link icon and paste in the URL.