Describe the first step taken by congress in proposing a bill to the house and identify the key players in this process. (site 1)

Bills can be introduced by members of Congress or Senate. Then it would be given a number to indicate if it came from the House or the Senate. Then it will be passed to a committee that is assigned to see any issue on the bill. The Chairman of the committee would give recommendations on what would be done with the first draft. 

After the review, the Committee will thoroughly study and see any related or conflicting laws. After the report, arguments of whether this is amendable or not.  It will then go to other Chambers where it would be handled to see if it can be approved. If all the concerned officials agree on the Bill, a Conference would be held where both Congress and Senate would agree or reject the Bill. The final bill would be sent to the President for approval. The President can release a veto or not. If a veto is given, the Congress can override it by having enough numbers  to create a quorum to vote.