So to answer your questions ....
The pattern I use is the Baby Surprise Jacket by Elizabeth Zimmermann, available from Schoolhouse Press
This pattern will make a jacket that will fit from around 6 months to 18 months.
While away on our holiday in the beautiful Forest of Dean last week, I cast on another jacket, the pattern really is addictive ( especially as the first one I knitted doesn't fit O and this one won't either ! will be looking for homes for them )
The pattern is easy ( honestly ) it really is all about trust.
I did join the BSJ group on Ravelry, which I do recommend as some of Elizabeth's terms really threw me but thankfully all the answers were there, along with photos of jackets in progress.
The folding of the finished jacket is really easy and with only shoulder seams to sew, how much better can it get.
Good news for those that need bigger sizes, Schoolhouse Press are now selling a pattern that covers baby, toddler through to adult ( mine is on its way .. yipppeee .. one that will finally fit O )
Please let me know if you have anymore questions.
So what you waiting for ...