I'm using Word and I broke the chapters individually and I noticed that majority of them are short-too damn short. Allow me to give an example: Chapter one: 14 pages Chapter two: 7 pages Chapter three: 14 pages Chapter four: 9 pages Now, I know that chapters are allowed their own natural length (so I've read on here) but I need help on how to add in more details and scenes and immerse myself in them. I have read what is written in the chapters but they really don't "feel" like enough. But I don't know what else to add.
Have you fully fleshed out each scene? A lot of people on this site ( and others ) complain about description. You can be sparse as long as the reader has a clear idea of where they are and what's going on. Have you layered the characters? Meaning that there's usually two levels the characters are working on - whats going on presently and backstory involving another or more characters - for instance in my ms the Main character starts playing nursemaid to his twin brother - that's the present action but there is friction between the two because they are both involved with the same woman, backstory which is slowly revealed. That gives your reader two things to constantly question - why is the twin sick, why are the twins angry with each other. Also, think about subplots. The backstory with the woman could be called a subplot.
First of all, get used to expressing length in terms of words, not pages. The number of pages can vary based on font size and style, line spacing and margins. Think about the very best novel you have on your bookshelf. Go look at the first four chapters. How are the elements @peachalulu mentioned above handled? How do they differ from yours? Look at a couple more novels in the same way. Your complaint that "they really don't 'feel' like enough" means that your writer's alarm is serving you well, but the issue isn't length so much as depth. Good luck.
Also consider how you're writing the scenes. Are you summarizing the events and moving on, or are you taking the time to let your character observe and react to what's happening around him or her? By that I mean, you can say that your character stopped to think about the creepy man in the cloak who just walked by, or you could go into her head and show her reactions to the event. It also depends on the purpose of the scene, and the pace. If it's meant to be an action scene it'll be fast paced, and it will likely have shorter sentences and fewer words. Slower scenes where tension is low will take longer to build. If your slow scenes are coming up short, look into why you might be rushing through them. Whatever you do, don't just add filler to up the word count. Flesh out skeletons with meat, not fat.
Scenes are something I'm still working out. But I've just started reading Scene and Structure by Jack Bickham, so I hope it helps. If I find something new, I'll be sure to drop it here. The advice above is all really good too. I would give the same advice, it's just a matter of learning to implement it. The best suggestion I have at the moment is to read books you thought were good, not for entertainment, but to see how the work. If you can, get ahold of some not so good books to see why they don't work.
I think what you need to do is go away from your computer, or wherever you write, and spend time ...a LOT of time ...visualising your story. Daydream it. Get it in your head, see it happening. Don't worry about writing it down, just think it out. People who get hung up on organisation, chapters, chapter length, outline, plot hook and other devices sometimes miss the whole point of what they're doing. These things are devices to help you tell a story. If you don't have a story, but only the vaguest notion of plot and character in your head, you're getting the cart before the horse if you start with the mechanics instead of the 'meat'. Get at least a few scenes fully fleshed-out in your mind. If you're the sort of person who likes to start at the beginning, spend a lot of time visualising your opening scene. Where are the characters when we meet them? What is happening? What are they saying to each other? How do they feel during this opening scene or chapter. Is something wrong? Or do they feel everything is perfect, and don't know something horrible is about to happen to them? What kinds of things are they concerned with? How do they express themselves, if they have lines of dialogue? How do they respond to what the other person says to them? How do they feel about the other person they are talking to? Get these visualised strongly, If you have a notebook, you might want to scribble these ideas or scraps of dialogue down for future reference. Once you get these kinds of details imagined from start to finish, then start writing. Keep what you've visualised in your head as you do. By the end of that first scene, you should be able to move on into the next, and so on. Don't stress out about all these structural details at this stage. If you do, you risk writing a flat, formulaic story with no heart. Get the heart in there first. All the other things can be shaped later on.
I don't know your experience level, so...your gut may be correct, or you might just be hung-up on something that doesn't matter. Very successful books exist with short chapters. I'm currently reading Asimov's "Foundation" series, and some of those chapters are only a few pages. If you start adding stuff in simply because it's too short, you will wind up having to cut it back out later.
When I have this problem, I go over the chapter and see where I can add more sentimental meaning. Find an opportunity to shine more light into your characters personality or history. If it's a chapter about buying something at a store, add some items into that store that can trigger a memory for the character. If it's an emotional scene, add some history... "I was almost as happy/sad/angry as the time when [add some backstory here]".
When you can post to the Review Room, I'd suggest posting something--something written for that purpose, if you don't want to use your book chapters. But if I had to guess, my guess would be that you're overusing narrative summary rather than scenes. For example: Narrative summary: They wandered through the mall, buying a few necessities for the apartment. Scene: Jane grabbed Joe's arm and tugged him through the entrance. "C'mon, we need a trashcan." "A trashcan? You want to pay money for something to put your trash in?" "What do you put your trash in?" "A grocery bag. It's free." "Eew." Jane kept on pulling, only letting go when they reached the center of an aisle marked with a looming overhead Housewares sign. "Look! Plastic in all the primary colors! Wire! Brass!" "Eew." The scene could go on for eighty more pages, and we could learn things about Jane and Joe's taste, the way they interact, how they feel about their homes, all sorts of things. Even if they're just in the mall so that you can have Joe kidnapped later in the parking garage, you can accomplish a lot more with the scene. Edited to add: You can also switch right back to narrative summary whenever you want, to cross over the boring bits, and then switch back to scene. Below, I have scene in blue and summary in red: "Eew." "So you want the wire one, then." Joe lost that debate, and the next one. Three hours, two wire trashcans, one dish drainer, and three sheet sets later, they headed for the parking garage. Jane frowned. "Who's that by the car?"