Checklist for deploying SSRS Reports:
1. Install SSRS. SSRS is installed from SQL installation media. If SQL is already installed, from Programs and Features Select SQL and choose Change.
2. Set SSRS Service to recover automatically in case of failure - ensure it starts automatically.
3. SSRS requires IIS for versions prior to SQL 2008; for SQL 2005 and prior, make sure IIS is installed and enabled.
4. After installation, access SSRS with the user who installed it - only this user gets permissions by default. Under Site Settings > Security add users to their correct security groups. Make sure you add the Domain Admins group as Administrators of SSRS.
5. If you cannot access SSRS through your browser, make sure you are starting your browser with administrator permissions.
6. If you still encounter difficulties accessing the SSRS site, make sure your SSRS site is added to your compatibility list or set your browser compatibility correctly - depends on the version.
Once SSRS services are running and accessible, make sure you deploy SSRS reports from GP. Here is a link to a really solid article on how to deploy SSRS Reports in Dynamics GP:
Nataraj on Dynamics GP SSRS deployment.