My landlord (who is wonderful) told me he'll be raising my rent at the end of my first year renting (December). I understand the concept of "unconscionable" raises, but are there any guidelines as to what is considered the norm in terms of percentage increases? For example, is 10% considered "the norm?" Thank you

There is no norm, for example where I currently rent it is going up about 25 percent this next year PLus you will have to start paying water.
Things like over head, things like the common aerea costs

In NJ the law is that the landlord is entitled to increase the rent but the increase must be "reasonable". So most likely a 10% increase would be considered reasonable. A 25% increase would most likely NOT be considered reasonable and would not be enforceable.

There is no "norm" for what is considered a reasonable increase. The judge would look at several factors, such as the length of time you've lived there and the increases (if any) in the past, the market rent for the neighborhood, any increases in the landlord's taxes and other expenses, etc.