As per requested, here is the guide.
First of all, please go to
www.blogger.com and login.
(if you have forgot your login email and password, please let me know, I will either help you to find a way to retrieve your password or send you a new invitation.)
You will go to this dashboard. Click the
NEW POST button.

Write whatever you would like to write and you can play with
the font size, color, type and etc. If you are familiar with
html, you can play with it. If not, I will recommend you go for
general compose way, at least it is more user friendly. Don't forget to
save your post from time to time before you accidentally close your browser or the browser lags suddenly.

If you wish to post a picture, click on the
picture button.
A
pop-up will appears on your screen, choose your picture. If you wish to upload more than one picture, click on the
add another image button. Then please select
the position and
the size that you want your picture(s) to be and then click the
UPLOAD IMAGE button.

Please wait for the uploading process...

Once it is done, click on the
DONE button then the picture will be added into your post.

When you have finished editing, click on the
PUBLISH POST button. If you wish to preview before you post it, you can go for the
preview button on the upper side of the right corner.

I wish this will help. If you have any further question, feel free to ask me again.
PY: I have spent more than 2 hours time just to do this post. I guess we will be seeing your first ever post in our blog in a very short while. You never let us down right? hehehe :p