Are we allowed to link to external sites

This may be a silly question, but I couldn’t find it in the rules. I probably just read over it by mistake.

A lot of users ask really detailed css questions that really can’t all be answered or want help over things that WP does not and should not support.

Are we allowed to link them to an external site that can help them? I don’t want it to seem like I am spamming by posting these links. Am I wrong? Or is this allowed if we are genuinely sending a user to a place better suited to help them?