What type of replication should I use?

Hi,

I have a need for a real time replicated database of our SQL Server based ERP system. The source database is about 500 GB in size. The new database will be used for on the spot production data analysis and real-time reporting / dashboards.

There is no need to update the source database with changes made by subscribers, but the replicated db might change during testing. There are no filter requirements either.

Is replication the correct solution for this requirement? If so, what replication method should I use?

What edition of SQL Server are you using? And which version?

source db is v10.50 (2008 R2) standard

You can use Transactional Replication, but it won't be real-time. It'll be 1-2 seconds behind usually but could be several minutes to even several hours behind if a large transaction runs.

Does that method create rowguids in the source table? The reason I'm asking is that I won't be able to modify the source tables.

Nope, but it does require a primary key on every table to be replicated. If you already have primary keys, then you are all set to use it.