Since 2012 some of the states have changed their rules for delegate allocation to the National Convention in July. Below is current map showing how each state will allocate their delegates to the National Convention:
Legend from frontloading.blogspot.com,
Convention: State will bind delegates to the national convention at a state/territory convention. Other conventions will leave the delegation unbound.
Proportional: State will proportionally allocated delegates based either on the statewide primary/caucus vote or on the combination of the statewide and congressional district votes.
Proportional with Trigger: State will follow above proportional rules but allows for a winner-take-all allocation if a candidate wins a majority of the vote statewide or at the congressional district level.
Hybrid: State will follow some form of winner-take-most plan (i.e.: winner-take-all by congressional district) or directly elects delegates on the primary ballot.
Winner-take-all: State will award all delegates to the plurality winner of the primary or caucus.
Each delegate will have to vote as their state primary instructs them on the first ballot. If no candidate wins 1237 votes to win the nomination, and a second ballot is required, delegates will be released to vote as they choose.
More details on the RNC rules for nominating our candidate here.