Moving to Latvia-permits, residency etc

My partner(British citizen) wants to move to Latvia in November. I'm Latvian myself, but I've been away for 5 years and don't know where to start to look for information to help him…
1 - How long British citizen can stay in Latvia? I've seen that only 3 months? How could he stay longer?
2 - I've seen on this forum, that from time to time someone posts about Latvian language courses. Is there going to be any in November?
3 - How about registering residency?
4 - and to work in here. Is there need for any specific documents or permits?
sorry for all these questions, but everywhere I've looked, there's no good information about all of this….
Thanks in advance

Residency permits are handled by the Latvian Migration office. It is also called PMLP
Their website is at this link: … permits/#1
If they will answer the phone, they can be helpful.