Letters of Offer
After a successful interview process a verbal offer is commonly followed by a written offer letter.
These letters should contain the title of the position being offered, the salary, clarification of relocation assistance, sign-on bonuses, benefits, and other specifics of the opportunity.
This letter will usually include the anticipated start date and contingencies, like passing an employer's physical exam. If non-compete contracts are to be signed as a condition of employment, make sure you review it prior to accepting opportunity.
It is good practice to delay a formal resignation from your current position until you have received an offer letter.