Conversation so far:
What was Jim Steranko's early art career like?
During the day, Steranko made his living as an artist for a printing company in his hometown of Reading, designing and drawing pamphlets and flyers for local dance clubs.
what did he do next?
He moved on after five years to join an advertising agency, where he designed ads and drew products ranging from "baby carriages to beer cans".
did he stay there long?
CANNOTANSWER.
What did he do next?
In 1966, he landed assignments at Harvey Comics under editor Joe Simon.
did he do anything else?
Steranko self-published it in 1970 in the limited-edition "Steranko Portfolio One".
did that sell well?
CANNOTANSWER.
Are there any other interesting aspects about this article?
I learned a lot from it and eventually went on to create a few comics of my own..
did his own comics do well?
I think Jim's legacy to Marvel was demonstrating that there were ways in which the Kirby style could be mutated.

Question: what was his big break?
Self-contained rewrite: what was Jim Steranko's big break?