Hi, and welcome to the forums. Are you familiar with the BW books and ethos? If not it may help you to have a read here to begin with to get a feel for things:
Starting EASY - all you need to know and more!Do you have a routine right now? Could you post it for us if so? Sleep training (getting him to sleep in the crib) is much easier when the routine is right - if he is overtired or not tired enough you will be fighting a much harder battle to get him settled.
Something it's probably helpful for you to know at the beginning is that we don't support CIO or other methods where LO is left to cry alone. That said, BW is not a no-cry method, but we do very much advocate you being there with your LO supporting and helping them to settle and gradually giving them the confidence to do it alone.
Something that I think will be important in your case is making the crib a fun and safe place to be. At the moment your LO probably doesn't have many positive associations with his crib so I would start by having him play in there with a few toys in the daytime for a few mins at a time with Mum or you right by his side. Gradually build up the time he spends in there, and then take him out whilst he is still happy (really important). As he gets more comfortable you can start to move away a bit, perhaps do a job in the room (folding clothes etc) while he plays, and then work towards just popping out for a minute or two and showing him that you come straight back.
Once he gets a bit more settled in the space, then you can start working on settling him for sleep in there. If you haven't got one already then start a relaxing settling for sleep routine, and put him down in the crib, using shh pat or PUPD (info in the link above) to help him settle. At his age you will likely see progress fairly quickly, within a week if you are consistent. He may skip naps altogether to begin with, or have very short naps, but if you hang in there things should improve
Naps vs nights....well Mum is right to some extent, naps and nights can be done differently. I know many LOs who nap only in the pram but sleep at night in the crib. But the flip side is that more chances to practice means you learn more quickly. Really it has to be your call - I get the sense from your post (I maybe wrong) that Mum quite likes the cuddle naps? If your heart isn't in sleep training it is very difficult, so I would say that this is something you do need to discuss and agree before you start as it really isn't fair to any of you, least of all LO, to keep changing the goalposts.
Hope that's helpful to begin with, let us know if you have more questions
