1. Do you need to unable SQL-Backup if you already using a 3rd party software utility to backup the SQL data drives?
--No. How would you do this anyway? It doesn't make sense.
2. If you do not want to shutdown SQL services for backup can you use Volume Shadow Copy as a solution to open files?
--No. Assuming you mean as a "solution to backup open files", the answer would be know.
3. What size would you recommended to use for the Transaction Logs DB if my Data DB size is 2GB
--Well, it depends. Are you going to run FULL recovery mode (do you need transaction log backups, or just daily full backups). Do you have a lot of concurrent, big transactions? Normally, for this size of database, I would set the initial size of the log file to 100mb, do a full backup nightly, set the recovery mode to simple, and let the log file auto-grow. I would then run a DBCC SHRINKDB once a day. This could vary greatly though from the above questions.
I am running Windows 2003 with SQL 2000/SP3. Obviously, I am not an expert in SQL so I appreciate your help.
--Read the articles on www.sqlteam.com, www.sql-server-performance.com, and watch the free webcasts on Microsoft's site. Also, read Books Online. People always laugh at me when I say that. You need to though....from start to finish.
When life gives you a lemon, fire the DBA.