Go to Picasa:
http://picasaweb.google.com/home
on the top bar click upload, it is in the centre. Choose your file and upload it. Your photo is now in the Picasa webalbum.
Click on the photo you want, then look to the right of the screen, there is a column, click on "link to this photo". You do 2 things: size the photo and check box for hide album link, then you copy the "embed image" info and paste directly into your message. And Voila....

Do not worry, I had a really tough time getting this right, and then it was so simple once I figured it out.
Paulus,
I am still not sure how your terrain is set up, are you saying that the Hougomont complex runs along the long axis of the table, with a wide open left flank. Also will there be only play around complex, or you allowing for the French to be able to get to the north of the complex.
I also do not see a rule in Lasalle for passing through a Hard Obstacle like stone walls, are you writing one, or can they only go through the gates and if that is the case how will they do it. I believe that there are both hard cover and soft cover rules in Lasalle, will you apply them to different parts of Hougomont complex? Finally how do you actually work the artillery, the max range is 12 bw for cannon, which I would believe in 15 mm gaming would be no longer than 16".
Anyway it sounds very exciting.
John