Thanee
First Post
While dcollins is polling about the individual levels, I'd like to ask about complete spellbooks. 
Let's assume you are an 18th level human generalist wizard (you started at 1st level with a 16 Int), you have access to the PHB 3.5 only to pick spells from, and you have scribed only a few more low to mid level spells into your book.
You have all 0th level spells,
8 spells each of 1st through 3rd level,
6 spells each of 4th through 6th level, and
4 spells each of 7th through 9th level.
Keep in mind, that you have built that spellbook over time, so pick spells that are useful for the respective level at which they have been chosen also, but of course you have always kept an eye on the higher levels as well.
Which spells are in your book now?
Spellbook:
0th - all spells;
1st - <spell>, <spell>, ..., <spell>;
2nd - <spell>, <spell>, ..., <spell>;
3rd - <spell>, <spell>, ..., <spell>;
4th - <spell>, <spell>, ..., <spell>;
5th - <spell>, <spell>, ..., <spell>;
6th - <spell>, <spell>, ..., <spell>;
7th - <spell>, <spell>, ..., <spell>;
8th - <spell>, <spell>, ..., <spell>;
9th - <spell>, <spell>, ..., <spell>.
Feats: If some feats would be important for your spell selection to make any sense, list them here.
Bye
Thanee

Let's assume you are an 18th level human generalist wizard (you started at 1st level with a 16 Int), you have access to the PHB 3.5 only to pick spells from, and you have scribed only a few more low to mid level spells into your book.
You have all 0th level spells,
8 spells each of 1st through 3rd level,
6 spells each of 4th through 6th level, and
4 spells each of 7th through 9th level.
Keep in mind, that you have built that spellbook over time, so pick spells that are useful for the respective level at which they have been chosen also, but of course you have always kept an eye on the higher levels as well.

Which spells are in your book now?
Spellbook:
0th - all spells;
1st - <spell>, <spell>, ..., <spell>;
2nd - <spell>, <spell>, ..., <spell>;
3rd - <spell>, <spell>, ..., <spell>;
4th - <spell>, <spell>, ..., <spell>;
5th - <spell>, <spell>, ..., <spell>;
6th - <spell>, <spell>, ..., <spell>;
7th - <spell>, <spell>, ..., <spell>;
8th - <spell>, <spell>, ..., <spell>;
9th - <spell>, <spell>, ..., <spell>.
Feats: If some feats would be important for your spell selection to make any sense, list them here.
Bye
Thanee