We have a 7 month old puppy... I have found it rewarding but also quite challenging. They are needy and sometime irritating, they need a lot of time and effort. I knew that but I wasn't really prepared for the reality of it - I don't go out as much as I used to and I certainly don't have the freedom that I used to have. The other thing I found difficult was that everyone has a different opinion on what's right and wrong, what you should do and what you shouldn't. That didn't help me - it made me quite inconsistent with some things that were probably important (e.g. training recall, crate training, leaving the dog alone). Now, I only really ask advice from the dog walker (who knows my dog) or the vet (who has years of training). Based on that, here are my top tips (some things we did, others we didn't).
We read the Pippa Mattison Happy Puppy book and took quite a lot from there it's probably worth a read.
When you get the puppy home don't let it's feet touch the floor until you put it down in the place you want it to pee (outside) wait until it pees/poos, treat praise and come inside. Take it out every 20/30 waking minutes and praise when it pees/poos (you need to watch like a hawk). I also slept in the same room as him for the first week (until he slept through without crying in the night). After that I set an alarm so that I could take him out to pee in the middle of the night (for about 3 weeks). It was really tiring but I'm glad we did it as he was completely house trained in less than a month.
Make the crate really comfortable, warm and dark. Before you collect the puppy put a couple of treats in there, some water and a good puppy chew toy. When you bring the puppy in (after it has peed) let it explore the crate and hopefully fall asleep in it. When the puppy is in the crate it shouldn't be disturbed (except maybe to be taken outside to pee).
Get the puppy used to being on it's own from the start. We didn't do this and I really regret it. I think leaving it regularly and gradually extending the time it's alone is sensible. Make the crate fun, use a kong for when you're out, hide the occasional treat/new toy in there and feed the dog in there - regularly closing the crate when you're in the room as well as when you go out.
Work out what's really important to you training wise and train only those two or three things to start with. For me that's recall (and I screwed up/wasn't consistent and had to start again from scratch), wait and sit. You do have to be 100% consistent and on it all the time but it'll mean that you end up with a well trained dog.
whoa - that was long. Hope it helps!