Entitlements is essentially getting permission from the municipality to build what you want on a site with regards to use, density, building height, setbacks, traffic impacts and environmental issues. Each municipality has their own ordinance that defines the process to entitle you to build your project and most of them are different.
The quick answer is to locate a site then determine if it is a parcel in a city or county, then contact the Planning & Zoning Department that has jurisdiction and they can guide you through their process. Essentially this is my job. Our acquisitions department locates sites throughout the midwest and east coast and lets me know how many units they desire. Then I contact the Planning & Zoning Department, Building Department, Utility Companies, Highway Department, Board of Health, etc., basically any department that I can think of that would need to review our plan. Some municipalities are more user friendly than others. For instance some P&Z Depts. consider themselves a "one stop shop" and they have a nice neat little packet that explains the entire process to you. Others have poor communication between the different departments and you are own your own to obtain every reivew and approval you need.
My first question is always, what is the current zoning? Then, is multi-family allowed in the current zoning? If the property is zoned properly then great, move on. If not then you will need to follow the rezoning process. Usually a boundary survey and legal description are required, beyond that it depends on the municipalities requirements. Sometimes that's all you need, other times you need a detailed site plan and some elevations of buildings, depending on the size and scope of your project. Detailed plans are being required more and more. The reason is a developer used to be able to turn in a survey and say I would like to build apartments on this site and the city would say okay without knowing what they will look like or how tall they might be. Now days, neighbors and the adjacent public are becoming more outspoken about what gets built around them and the zoning process is the only time they get a chance to voice their opinion. So now developers have to make commitments about what they build, like, how many buildings/units, how much brick or stone, and these committments are then recorded as a requirement.
Even though all cities are different the rezoning process is probably the most consistant. Beyond zoning, it's a crap shoot as to the process and time frame required to obtain entitlements. Some cities can get you through in 6 months and others can take 2 years depending on how many agencies have to get involved.
I'm rambling a bit now and I know you were looking only for reference material which Jon pointed out the Urban Land Institute which is a great resource and the place you should start. After you poke around there a bit feel free to post more questions here. After all that's what this website is for and no better people to ask than those with experience.
