If you use Word, there is an option under Tools, Letters & Mailings (or Envelopes), Envelopes and Labels, whereby you can set up a table for the correct size of your label (Avery J8651)... Click on the labels tab and choose this particular label, then type the address in the box. If you then click on *Print* you will be able to print out direct to a page of your labels (obviously insert a sheet of labels into your printer), but I often find it easier to click on New Document, then you can save the file. What Word is doing is creating a table that will limit each cell to the same size as your label.
Once you've created the labels document, then you can insert the picture that you want into the table.