I am looking for information about how SQL Server actually handles query execution in finer details (like what data is kept in buffer/memory and how does it decide to get fresh data even if there is an update change in only one column of a table involved in a query etc)
If anyone knows sources please let me know?
We have an web application using sql server 2000, it has heavy frequent reads almost 70% of the tables(dashboard) every 30 seconds. and at the same time lot of writes are happening.
Please let me know any tips for optimization of above scenario?
No one is going to be able to give you an answer on how to solve your optimization problem. This requires access to your database server. To solve your problems you need to understand roughly how the database works, and for this you need to do some reading.
On-line resources are OK, however the following three books are priceless. The first two books have very detailed information about how SQL Server works. The last ones is a guide of how to write queries but with a discussion on how the engine views queries as well.