Welcome aboard Damien
The basic tool for drawing in Shipbucket scale is of course some kind of drawing tool. The easiest to use and with a very short learning curve is MS paint (the one which was an integral part of Windows XP is best, IMHO). Many prefer either Gimp, or Paint.Net. Some use higher end tools like Photoshop, or others, which are more harder to learn to use.
this old tutorial
was created by Gollevainen was published in the very old Shipbucket forum, and can help you in your efforts (provided you use MS Paint).
You can also search the forum for other tutorials (some made by Ace) on how to draw some ships and how to use shading.
Thank you Kim for the crest
"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"