Newb unlock questions

[Vertigo50]

I've been jailbreaking for years, but haven't had a need to unlock, so I haven't stayed current on that info. Forgive me for asking a few newb questions, but I'm trying to understand unlocking a little better as I may want to unlock before selling my iPhone 4 to upgrade in June.

I have 3.10 firmware right now, which it seems doesn't have an unlock, correct? Is there one expected soon?

In the future, how do I update and jailbreak without updating the firmware? I'm assuming this is the best method to maintain the ability to unlock until the unlock is updated?

Thanks for any help you can give, guys.

 

[Leet Apple]

They have an Unlock Ready but they are waiting for iOS 4.3 to release first

in the future use Pwnagetool to Update and save your baseband

 

[Vertigo50]

Don't people sometimes post torrent files of the updates without the baseband update included? Is this a bad idea, and if so, why?

 

[eastercat]

If you have the appropriate blob, you can use that and tiny umbrella to update the iOS without updating the bb.
Are you referring to custom iOS? These are made with pwnage and doesn't update the bb. If you can find a trustworthy site to d/l it, it's fine. Because I have a Mac, I made my own; it works great. I recommend finding a friend with a Mac before looking for one online.