Assuming that by tips you are referring to entering Argentina. Beyond that, there is too much info to comment, but searching here is a great way to read up on many different experiences by many different riders. If you have specific questions, you'll have a better chance of getting answers,
As far as entering countries go, it's pretty straightforward, you shouldn't have any problems. Assuming that you are on the Malaysian Airlines flight from Jo'berg or Cape Town?
If you arrive too late to pick up your bike same day, you can cab into town and return next day. They are used to clearing motorcycles so even if you Spanish is poor you can find the cargo terminal (walking distance from passenger terminal) and then bumble your way through the process. It's basically fill out a few forms, get a few stamps,wait around for the right guy to say ok, pay a couple of fees, and then you can assemble your bike and ride away. If you want a detailed description, then I'm sure someone has posted one here, use google to assist with your search.
For a good place to stay, you can cab to Dakar Motos. It's not the ritziest place, but great for bikers and they have kindly housed many a rider over the years and if you happen to run into any issues with customs they can assist.
Where are you headed? Staying in South America or heading all the way up?