And for me, as I've never done this before (last dog was older, dog before that I was a feckless teen and she was horribly untrained) 
He has been with us 3 weeks. He is lab x with/possibly beagle + probably staffy, castrated. He didn't have any training when we got him, but is a sweetie.
He is house trained, but doesn't really know how to ask to go out - just vaguely sits near back door. We're just careful to take him out regularly.
He has learned 'sit' and is very reliable as long as I have treats to hand! He has great recall, and runs to me to sit and get a treat the minute I call him, even 8/10 when playing with other dogs. Unless its his favourite friends.
He can sit and stay, if I have a treat, for about 30 seconds - a work in progress.
He is learning to 'sit' when greeting, though will still jump up at kids especially when excited to see them in the morning. He's not bad on the lead, except when scared or reluctant to go out - then he just sits down or pulls back towards the house.
Should I be teaching him 'lie down'? 'Heel'? Anything else I'm not expeienced enough to think of?
Am conscious he will soon be a big teenager, and want to use this window to help him be the happiest, most welcome dog possible. Especially given that he is going to be a bit of a staffy-cross ambassador in the area I live in 