ASX Historic Data. Help!

Help!

I am trying to get into share trading from the ground up.

What I want to do is download historic ASX data, insert it into a database, and then try out some formulas to look for patterns I might take advantage of.

I am a software developer, so I have the skills to programatically do this, but am I reinventing th wheel? Are there products out there that will do what I need? What do you recommend?

Anyway, I managed to FTP historic data from StockWatch. The only problem is that the data seems to be quite dodgy. For instance:

1/ While data for weekends IS excluded, other (annual) holidays (like Australia Day) are not! Why? I thought that any stock program would have to ignore holidays to achieve accurate charting. Instead, data seems to be duplicated from the day before!

2/ A lot of data is missing from the CSV files! Quite often the open, low, close, high prices are missing! Argh! What can be done in these situations?

Is there a better source for end of day data?

Is there a source where one can download stock sector information? ie. I need a resource that matches stocks to their sector, like Telstra to Telecommunications.

Please help!

Jerome