go to photobucket.com
open a free account
when you open your account chose the pics from your computer which you wish to upload,then click upload
it might take some time to upload the pics if they are big(bigger than 1mb). pics around 200-300kb are uploaded fast.
after you finish uploading, come here to skyscrapercity.
write your response to the thread you like and press the insert image button.
copy the second link below the image you want to upload from photobucket and paste it to the insert image space here.
click submit reply and voila!!!your pic is posted!