Monitor lizards

Question
I have two questions:
I want a baby monitor lizard. Are they deadly as people say because of there samanila or do I have nothing to worry about.
Next I own two rats. Now if I raise this lizard with me all the time will it bite me if the sent of rats is on my hand. And will it get me sick ?

Answer
Well, the first thing to consider is that monitor lizards in general aren't animals that are really suited for beginning reptile keepers.  You should gain several years experience with easier animals first.  (Leopard gecko, crested gecko, etc).
You should do TONS of reading on monitor care, check out how breeders keep their animals, learn about Retes stacks, etc etc.

After THAT, choose a smaller species such as an Ackie to get started with.

All of your questions about salmonella and bites will be answered during this process.  Owning a monitor is fairly big commitment, and a 'baby monitor lizard' grows up in around 3 years to be an adult monitor lizard.

There are many different species of monitors, and some are, indeed, dangerous.  Crocodile monitors should probably not be maintained outside of zoos, for example, because they have teeth like razors that are very long, and even a nip can slice to the bone and cause nerve damage.  Water monitors are simply massive, so the potential is there for serious injury, though they can often be very tame, and make excellent pets.  Nile monitors are high strung and aggressive, and also large.  Timors are small but flighty.  You need to understand the species you're getting, you have to be fully prepared to raise it to adulthood and house it appropriately, and feed it correctly--and you need to get it from a reputable breeder.  It will not be inexpensive, and it will require a lot of learning.

Your rats will probably be deceased of old age by the time you have the knowledge and equipment to care for a monitor properly.  That's the simple truth of it.

Salmonella is bacteria that is a common cause of food poisoning.  In order for salmonella to make you sick, you have to ingest it.  Your chicken dinner is a much greater threat than a lizard.  Wash your hands, and there should be no problems.
Same is true of rats--wash your hands after you handle them, and the lizard won't smell them on you.