Question about blog etiquette

When you stumble upon a blog you like, can you just link to it from your blog without informing the blog owner, or do you ask first? I’m new to blogging, and I searched the FAQ on the blog site and I searched all forums here and didn’t find anything.
So which is it? Ask first, or just add?

Just add. You can then send a message if you want that they were added, but it’s not necessary.

I have never asked anyone but I do have several people who have written to ask or tell me they’ve linked my blog.

For the most part, I save blogs I like in my “Favorites” list on AOL. I do have a few Dopers as LiveJournal friends.

I have no problem whatsoever if people “friend” me.

Thanks, guys. I went ahead and added them without telling them.

If a moderator happens along, please close this thread. Thanks.