1)You can get the service name from your .ORA file (Where ever ur Oracle installation folder is) or if click on ur if u click on databases on ur enterprisemanager console, on right side of your grey console window it will give u serice name under TNS Descriptor or Service Name:

2)Assuming u have ur Oracle backup file(.dmp), u will have to restore it using "imp" utility. U can look up that in google.

From ur DOS Prompt,

A)C:\SET ORACLE_SID=

B)C:\SET ORACLE_HOME=c:\Oracle\Ora92

C)imp File=E:\UrBackupFilename.dmp Indexes=y Log=E:\Logfilename.log userid=UserName Pwd=UrPwd FROMUSER=UrSchemaName TouserUrcurrentSchemaName ignore=y rows=n Statistics=Recalculate

Before U run Step (C), U have to create ur TableSpace and user in Oracle

3)After Step 2 is successfully done, where ever ur Sql is installed, u have to Install Oracle client tools and then use DTS import export utility to import tables and their rows into Sql server.

I just have summed up whole process, it will be lot more complicated when u actually do it. But u can use it to research more about each n every step in detail(to get proper syntax etc etc)