Can someone please let me know the deadline for maintenance exams?
I hold admin certificate from winter 2016 so until how long I have to give maintenance exam?

Can someone please provide information on salesforce developer 1 exam?
such as Link for mock test, even websites that sells peactice tests? OR what should I search on web for (e.g., mock test for force.com developer or mock test for force.com advance developer?)
I would really apprecite some advice. Thank You.