Any recommendations for any Windows and/or Linux tools to help
normalize a database? It's essentially a combination of several
existing databases (that have some related information) into a single
one.

Also, recommendations for books on the theory of database design,
especially a temporal relational database, would be appreciated.

Finally, say you have a piece of info that's a direct consequence
of other pieces of info (>1) in a table, but that is quite computationally
intensive to calculate. Would putting it into the table violate
3NF and the transitive dependence condition? I'm gathering that this
isn't the case. I'm uncertain, however, how best to document that
it's a function of other information in the table. A separate table,
with a concatenation of the functional dependencies being the
primary key?

-Chris

DBDesigner (google it) is a very powerful modeling tool available in XP and Linux. It's free.

computationally expensive? store it

if you don't keep any documentation outside the database itself, then i would recommend giving it a column name that makes it clear

create table dilbert
( id integer not null primary key
, name varchar(30)
, foo integer
, bar float
, qux decimal(10,2)
, calculation_results_based_on_values_of_foo_bar_and _qux integer
)