For those that are pregnant, or already had siblings. How did you prepare yourself, and your son/DD for the arrival. At the moment I staying at home with my son and we play a lot, but I know that when the other baby arrives, we won't be able to do it and he won't take it well. He is a very sweet boy, he is used to share his toys, since he was in a daycare. He also listens very well and helps a lot at home but since we told him about the baby he is acting off all the time. Throwing tantrums that we have never seen before and asking me "if he is my little baby". Also I don't have a lot of support, I can't count at all on my family and my husband family is there but they work and can't help me too much. My husband is taking 2 weeks after the birth to help me with the house and our son (we think I probably will have another c-sec) but after that I am pretty much on my own. Was it hard? Did you still go out a lot with both children? How is the experience? What about a newborn with a toddler, almost a preschooler at home? Any advice

Thank you!
Mummy to 2 wonderful children
Noah (2011) & Lily (2014)
Re: Preparing for a new baby
The best thing that I did was start taking them out on my own as soon as I physically felt able. It really helped to find a groove/routine for getting in and out of the house/car/stores while DD2 was still an infant and would sleep a lot on the go. Even just a short car ride felt like an accomplishment. By the time DD2 was two months, I was fine taking them on my own for a short outing to a local park.
That's the other thing, we kept outings short and expectations low. Even now, if I feel like I am getting stressed, we simply pack up and head home.
At home, here are a few things that helped me the most: 1) I ALWAYS made sure DD1 had a snack and drink BEFORE I sat down to feed DD2. 2) There was a LOT of TV in the beginning. I had to suck it up and just go with it. DD1 is high energy, and it's the only thing that would keep her quiet while I would settle the baby for a nap. 3) We set up a wireless camera in the living room. I can watch DD1 on it from upstairs while I feed and settle the baby, without worrying about DD1 popping in to "help" with the baby. 4) Made sure DD1 was very involved in helping care for the baby from day one. 5) When DD2 is asleep, DD1 and I try to do something one on one that doesn't involve me doing chores around the house. Even just 20 minutes coloring or walking around the yard together makes her so happy and gives her some mommy attention.
Some days are easy, some are hard. Not sleeping and caring for two little kids was the hardest part for me, personally, for the first few months. But now we are at the point where everyone is sleeping a little better, and the girls play nicely together while I throw together a meal or do a load of laundry.
Pregnancy #3 after two prior losses in 2013
I always made sure to get DD involved in a new activity before tending to baby. At this age I'd stock up on arts and crafts from the dollar section of Michaels/joAnns/Target, play dough, paints, movies from the library, blocks/toys that you only get out for when the new baby nurses (all things that are for individual play). I would often put DD in her high hair with a snack and tv, also put her in the bath tub and nursed DS while sitting on the toilet watching her, and you can still read to DS or do puzzles while nursing.
It sounds like your DS gets a lot of one on one play with you right now, you may want to start prepping him by letting/making him play on his own more often.
Like Melissa said, outings will be stressful, be prepared for it, you'll survive.
Don't worry too much, the transition will likely go better than you ever expected. The first few weeks/ months are purely survival, do what you need to do and you'll make it.
Third, if you don't already have a baby video monitor, I highly recommend getting a wireless camera. We have a Foscam that I got for around $70 and an app called IP Cam Viewer that is set up on our phones and ipad. The bonus is that I can view the camera feed over 4G when I'm out of the house, so I can check in remotely.