Oh, yeah, this is normal. You're right, he's learning how to communicate more and exactly WHAT gets him what he wants. Please, don't become one of those parents who goes ballistic when their baby starts crying because he didn't get what he wants.
Now is a great time to really start talking with him and, if you're up to learning a new language, sign language basics is great. For example, my youngest started pre-school at 18 months and she can tell me at least a dozen words in sign language.
One good piece of 'learning advice' I got from my mother and yes, she did this to me too, was when I would start crying or throwing a temper tantrum, she would take me to my room to get away from what ever the cause of the issue was and sit me down & speak very quietly. I had to work at hearing her so I had to stop crying. If I couldn't stop crying, she would tell me "Okay, you have your tantrum here in your room. You can come out when you are done, understand? I'll be in the kitchen,".
The first time you try this he's going to follow you out so turn him around & put him back & tell him when he's done, he can come out but not before then. It's not punishment; it's giving him a chance to vent and helping him understand that you (and your husband) don't want to listen to his ranting. Give him his 2 minutes or how ever long he needs and let him come to you. When he does, simply ask him "Are you done?" If no, then he needs to go back to his room for a little while longer. Again, this is not punishment. Tell him you love him but you don't like his behavior. When he is done he can come out. (He'll tell you he's done now but be firm; if he hasn't stopped, take him back to his room).
When he's done, talk with him. He understands probably a lot more than you think. Go over the basics: Hungry, wet diaper, thirsty, play? What does he need?
As he gets older, you can simply tell him "No, I don't like your behavior" and walk away. Let him lie on the floor & throw his tantrum. If you walk away, I guarantee he'll stop. He's going to want an audience. My 4 year old still has her tantrums but every time she starts, I walk away to another room or take her to her room & let her cry it out. When she's done, she'll tell me what she wants. If I say no it usually causes more crying but since she doesn't want to go back to her room, she stops pretty quickly when I tell her to stop or go back.
It gets better, really it does. Talk with your husband about what kind of plan you BOTH will use with your son. It doesn't work if only one of you stands strong. "United we stand, divided we fall" is SOOOOOO true at this stage. Take some time off together, away from your son. Look into some creative parenting classes or Mothers Support groups like MOPS (Mothers of Preschoolers). Getting advice from other moms and 'mentor moms' can really help. :)