There are a couple of different types of passes. When my Mom was a manager at a
Disney Store she had a Silver Pass which got her 3 people plus herself or spouse into the parks on any day except blackouts.
Now, she works at WDW but just as a regular CM and has a Main Entrance pass which gets 3 people plus herself/spouse but it is only for like 12 admissions a year, or maybe it is 16. And there are blackout days. It used to be just used to be major holidays but starting this year there are a LOT of blackout dates. If the spouse's family is larger than 4 people the pass is good for the number of people in the family. It's good at all parks except the Japanese parks. At WDW, the CM can also get in on their ID.
The tickets you get are park hoppers. The CM/spouse is supposed to stay with the guests unless they are immediate family.
Also twice a year the CM will receive 2 tickets (so 4 tickets in total) that are one day park hoppers. These are good any time, no blackouts.
In addition to this, CM's can purchase passes, even APs, for friends and family for like a 5% discount. And tickets to the water parks, Disney Quest and Pleasure Island clubs for 50% but the CM has to accompany the guests.
Yes, there is a "friends and family" rate for hotels of either 40% or 25% depending on availability. If they are staying at the hotel at the same time/same room, the discount is 50%. Sometimes you can get the dining plan added on for 50% off. And sometimes there are specific deals (like 60% off Saratoga Springs or something)
20% off food if the CM is there for the meal at sit down restaurants, although there can be restrictions, like for lunch, only after 8:30PM. They often take away this during holidays and free dining. My Dad bought a DDE card and they just use that instead. At
Disneyland the discount is good at ALL restaurants, even counter service.
Merchandise discounts are either 20% or 35% if the CM is a manager or worked at Disney for 3 years. They are supposed to be for immediate family, but they don't really care, just let the CM pay for everything and settle the bill at home. In addition, there are a couple of CM only stores. Cast Connection is behind the Magic Kingdom and sells overstock and discontinued merchandise. Think an outlet store. In the back of Cast Connection is Property Control. This is where they sell old park/resort stuff for cheap. Dishes, furniture, bedding, video games, you name it. Then there is a "damages" trailer. All the stuff that gets broken in the park, or let's say a package was opened, ends up here and sold at 75% off. At all of these stores you need the CM with you but you can pay for things yourself (you can even use a credit card). They just need to see the CM's ID. Then there are Company D stores, several on property. Here you can get the CM pins, lanyards. They also have some CM only merchandise, but it's mostly for managers to pick up little gifts (non-Disney). Also twice a year are 2 SALSA sales (Spend a Little Save A lot) which is the same stuff as in Cast Connection but even better deals. And there are several "Pin Parties" where pins are sold at 75% off. The SALSA sales are only open to the CM/spouse the first couple days but it's like a 2 week sale. Sometimes the pin parties are CM only (like if it is held backstage in a park) but the most recent ones have been in places where they can bring up to 6 people with them to shop.
Then there is the cast holiday celebration booklet. That gives one admission to a major park, one admission to each of the minor parks, one 50% off in-park dining, one 50% off resort dining, the merchandise discount gets bumped to 40%, free photo, 6 free popcorn/drink, the hotel discount for a room with a CM goes up to 60%. These things are usually blacked out around the Christmas/New Years but they are good Oct-until then, and then after New Years - Feb (blacked out again around Veteran's day)
Aside from the parks, CM's can also buy discounted tickets for the AMC theater, other area attractions at Company D. They also get discounts on the
Disney Cruise Line. The CM has to be sailing but can reserve up to 3 staterooms. There are different kind of rates, the best one is "space available" but what categories and dates available only come out like 6 weeks in advance. We've done 2 cruises, including the Taking the Magic to the Med cruise, with my parents. Both times we got a Cat 5 for LESS than what it would cost us to book a Cat 12 on our own.
All the CM discount info is available on the Cast Portal, including blockout dates, cruise rates, etc.
And yes, if a CM is willing to share their discounts with you it can be quite beneficial. I tend to still buy an AP so my Mom can save her tickets for when other family visits, but I have quite the pin collection due to the pin parties.