"This historical book is very important to us."
Translation:הספר ההיסטורי הזה חשוב לנו מאוד.
Personally, I think that "חשוב מאוד עבורנו" sounds the best, but "עבור" (and all of its forms) isn't very common this days.
Out of the two, "חשוב לנו מאוד" and "מאוד חשוב לנו", I belive that the last is more common when it comes in the end of a sentence while the former is more common when it comes in the beginning of a sentence.
However, following your question I tried to find some information on the The Academy of the Hebrew Language website and it seems that "חשוב לנו מאוד" is the only correct way to formulate it, so I assume that "מאוד חשוב לנו" created under the influence of foreign languages.
What word is מאוד modifying? If it's modifying חשוב, shouldn't it come immediately after, or immediately before, חשוב? How can putting לנו in the middle be correct? Is חשוב לנו considered an indivisible phrase that מאוד is modifying?
[Disclaimer: I'm not contradicting Hamutaltul! I'm just saying that his answer doesn't make sense to my English-speaking brain without more explanation, and am asking for that explanation. To me, (very important) to us makes a lot more sense than very (important to us).]