You decide to look around outside the mansion first. After all, you don't want to run right straight in and into some type of trap.
However, someone is probaly going to notice a strange man walking around in their yard. Luckily, you were prepared for that.
As well, as the two books, you had also brought a backpack with you on this trip, for carrying the books, and one other thing.
You quickly sit down and pull the Book of Beast out of the bag. Then, you strip off your clothes, leaving you completely naked, and put those in the bag. Then, you pick up the Book of Beast and open to the third spell.
"Shape!" You whisper as you change yourself into a raccoon. After all, raccoons are dark furred, so would be hard for someone to see. Plus, even if they did, what would be surpising about a raccoon coming out of the woods and approaching a house in the middle of the night?
You then push the book back into your backpack, and attempt to get the shoulder straps around your back. It takes a few tries, and the books are heavier in this form that you expected them to be, but eventually, you have the backpack on, while as a raccoon. Now you should be able to explore the area around the mansion without drawing to much attention. As long as no one gets a good enough look at you to make out the backpack.
You make your way up to the mansion, sticking to the shadows as you look around. As you explore, you find two security guards patrolling the grounds. One of them shines a flashlight on you, but mutters "just an animal" and continues on his duty. So far your plan seems to be working.
You make a complete circle around the house, and find there is one more security guard patrolling the back yard.
So far, from what you've seen while scouting the area as a raccoon, there are a few ways you could get into the house.
You could of course try the front door.
There's also a backdoor though it may be locked.
There's a cellar, if the cellar connects to inside the house somewhere you could go in through there.
There's an open window on the second floor.
You could always climb to the roof, and try the chimney.
Some other things of interest you noticed.
There's also a garage seperated from the house.
There's a large garden north of the house.
There is another building, which seems to be an indoor pool.
There is guard house.