I am still in the planning stages and have not decided which database program to use (Linux, Windows, etc).

For the time being, can I enter my data into a spreadsheet such as Excel, and easily import it into my database later? I do not want to have to re-type the data. Do db programs have a simple way to create records from existing files (spreadsheet, delimited text, etc)? What temporary file mechanism would be best?

Doesn't really matter

Do db programs have a simple way to create records from existing files (spreadsheet, delimited text, etc)

Most DB servers don't, but there are admin tools that do.

You can check-out "Load Data" command in MySQL. The best thing you can do is to try the command with a single record (row of your .csv or .txt files) to be sure that every data goes into the right field of your table.

http://www.classes.cs.uchicago.edu/a...;20your%20data

what type of site are you going to create? If it is a directory I know directory scripts such as phpmydirectory have an import feature which you can use to import data from a .csv file. I populated my directory site by uploading the .csv file of 24,000 entries & then accessed the phpmydirectory admin panel to import the data. It was a breeze & it runs on Linux/PHP/MySQL.

Creating the temporary data in excel files should not be a problem. Your requirement is a very commonly needed functionality and hundreds of tools are available to do that.

Search google for excel to mysql or excel to ms sql to see the results, the tools should not cost more than $50 or so.
--Amit.