I've attached TSA's regulations for airport security. You can go through the list on any subject regarding what is allowed. I know this may sound crazy but, keep in mind, 3 ounces of shampoo in a 6 ounce bottle is still going to be confiscated! Watch the size of your containers. If you are carrying liquids (i.e. bottle of wine, baby wash, extra conditioner or sunscreen, etc...) you can check your bag and it will not be a concern.
Any electronics will need to be removed from their bag and placed in a security bin. That includes, phones, cameras, laptops, even kid's handheld games. Wear easy-on/easy-off shoes as they will ask you to remove them.
Your car seat may fit right in the seat on the plane or it may not. It may be worth the try; Generally, your stroller can be taken up to the door of the plane. As far as luggage limit, google the specific airline. Generally, people with small children travel with more stuff.
The MOST important thing that you can do is give yourself, AT LEAST two hours, before your flight departs, especially if you are not familiar with all the proceedings. If someone can drop you off at the departure door, at the airport, (especially if at MIDWAY!), your life will be sooo much easier,otherwise, you will have to park a car, unload, board a bus, unload... etc... you get the picture.
Stay calm. Ask for help. If you, by chance, are going on Southwest Airlines, remember that you can pull a boarding pass EXACTLY 24 hours (do not wait a minute longer to start trying!!!) in advance, online. This will benefit you because Southwest no longer has pre-board privileges for people with young children so you will want to get the best possible boarding number you can.
http://www.tsa.gov/311/index.shtm