Here is the Office of Citizenship and Residency website: Check here:
There site has the information required, but sometimes doesn't have all of the details. Look at VISA information and Residence-Permit registration.
There isn't much part time work, as the economy is slow and unemployment here is high. If you're English is good then you can consider applying to teach.
Hi There Riga is a beautiful small city its sut like a place which we see in the animated movies a fairy land .Hey I sure would like to be your friend you should really come to Riga and Ill show you around.