'Novel' is a common noun or an adjective (there are two uses) and as such, should normally only be capitalised when it is at the start of a sentence (as I have done for this answer). This is the case when it is a noun, as in example 1, or an adjective, as in example 2:
1. I have just finished reading the latest Margaret Atwood novel.
2. That's a novel way of eating cornflakes.
It is possible that there is a very specific situation where it should be capitalised; for instance, there is a magazine called Novel, in which case a capital N is correct.
Have should be capitalized if it is the beginning of a sentence. Summer should not be capitalized.
It should only be capitalized if it forms part of a title.
Yes it should be capitalized.
The first 'c' should be capitalized.
Yes it should always be capitalized.
No it shouldn't be.
No, the word "novel" does not have to be capitalized in every sentence. It should be capitalized only if it is the first word in a sentence or part of a title.
Have should be capitalized if it is the beginning of a sentence. Summer should not be capitalized.
It should only be capitalized if it forms part of a title.
Yes it should be capitalized.
The first 'c' should be capitalized.
Yes, it should be capitalized.
Yes it should always be capitalized.
As an abbreviation it should be capitalized.
Yes it should be capitalized.
No it should not be capitalized.
No. It should not be capitalized.