I posted this answer to somebody else a couple of days ago...I'll copy it here for you. Good Luck!

First thing you need to do is set up a photobucket account. It's free. www.photobucket.com.
Then scan your plan and save in My Pictures. Then go back to Photobucket and click the box that says "Choose Files." It should take you back to your My Pictures files. Double click on you floor plan and it should start uploading to photobucket. Once you have saved it there,highlight the html code and right click to copy and then go to your post on the forum and right click again to "paste" the html code in your forum message. When you preview your message, you should see your photo there.
Hope that was understandable!

Join a free service like photobucket. After you upload a photo to photobucket it will provide you options. Choose the third one down (html) and copy the supplied url. then post the url in your message. voila.

Go to http://www.tinypic.com

Hit the Browse button.

Browse your computer and select your desired picture.

Hit the big green UPLOAD NOW! button.

When it's uploaded, copy the code you see in the first box entitled html for websites.

Paste that code into the Message box here on a GardenWeb post.

Done!

You don't have to use photobucket. There are plenty of free sites where you can store your pictures on the internet. Or possibly even your internet provider account (Earthlink, Road Runner, AOL, etc) may provide that service. Once you have your picture saved to the internet somewhere, you provide the link to the picture. For example, the following would post my picture ...

<img src="http://www.geocities.com/sno_bunn_y/kitch1-2.jpg">;

{{!gwi}}

Which I am currently asking for suggestions on, by the way ! . . . http://ths.gardenweb.com/forums/load/kitchbath/msg0623073132399.html?15

The important thing is to actually link to your picture only. One easy way to get the web address to your picture is to right click on the picture, choose properties, and then copy the web address. For example, <img src="http://a820.g.akamai.net/f/820/822/1d/i.ivillage.com/adsales/images/ivillage_88x31.gif">; would give you ... .

You can practice posting pictures in the test forum ... http://ths.gardenweb.com/forums/test/

I've figured out how to post pics, but they come out too big. I found the edit feature in photobucket and tried to resize, but they still come out too big. What am I doing wrong? TIA

Add either a width or a height measurement. (Only use both if you know the correct ratio to use)
For example, if I want to make the picture smaller, I can use the following ...

<img src="http://www.geocities.com/sno_bunn_y/kitch1-2.jpg"; width=200>

{{!gwi}}

However, I would not specify height & width unless I knew the correct ratio, or the picture could come out like Stretch Armstrong . . .

<img src="http://www.geocities.com/sno_bunn_y/kitch1-2.jpg"; height=200 width=400>

{{!gwi}}