My favorite mods (not in any special order):
1. Frostfall: It basically makes Skyrim's weather effects realistic. You can make it matter how much armor you're wearing, what kind of armor, etc. Depending where you are in Skyrim, the weather effects will act accordingly. So if it's raining, you'll eventually become soaked. If you're in Winterhold and not taking care of staying warm, you could die of hypothermia. And swimming up north is out of the question lol. If you get this mod, I suggest some kind of cloak mod so you can make fur cloaks, hoods, helmets, etc. Goes well together. You can also camp out and build fires for survival.
2. Realistic Needs and Diseases (I paired it with his other mod that redoes inns and taverns): Now, you gotta eat and drink like a normal person. You also must sleep. Your character will get hungry, thirsty and tired over time. If you drink without boiling water, you could risk disease. If you eat raw meet, you risk disease. Food can also go bad after a certain amount of time. But of course you can change settings and make it either easier or more strict. THIS WORKS AMAZING WITH FROSTFALL. Also, now when you drink mead or ale or wine, it actually takes effect. You go from dizzy, to drunk, to wasted, to blacking out. Your character will stumble and all that.
3. Realistic Blood (forgot what it's called): basically makes you stabbing someone slightly more realistic. More blood. And the blood is darker, as if the NPC's are actually bleeding out now. Blood drops on your screen as well ifyou'd like. When you kill frostbite spiders, they actually have a cool green liquid oozing out of them.
4. Wet and Cold: Works well with Frostfall too. Now, when it's snowing, you can actually see snow gather on your character's armor. When you're cold, you actually see your breath. If you're freezing, you'll see that too. Very cool. When you're wet and coming out of a lake, you'll actually see drops of water fall from your clothes.
5. Amazing Follower Tweaks: This mod is amazing, especially if you wanna be a werewolf or vampire. First, you can control their outfits, like what they wear in the city or out adventuring or in the home. You can make them do so many more things, from dancing, to kissing you, to tons of other stuff. If you're a vampire or werewolf, you can make them one as well. You can also have more than one follower. In my werewolf character, I had a whole pack with me. I was alpha and the rest were my pack. They would change into beast form whenever I did.
6. For werewolves- a mix of Heart of the Best mod, Moonlight Tales mod, and Werewolf mastery mod.
7. For the woman body, face, and hair, I use all of these following mods: (they work together well)
DOMINIONIZED UNP female body
Better Females by Bella Natural Edition - UNP no makeup (you need the UNP version so it is compatible with the UNP body mod)
The Eyes of Beauty
Apachii Sky Hair
I also always add the mod that makes your character have footsteps. I also enjoy Climates of Tamriel.
As far as managing mods, here's what I've found to be the easiest and most efficient because I suck with computers:
1. Download Nexus Mod Manager from the nexus mod site. Click "Install NMM" on the top of the nexusmods website. After you get this, you can download most mods on the nexus site by just clicking "download with NMM" very simple.
2. Also download LOOT. Loot will organize your mods for you since order matters. So once you have a couple mods downloaded and running in your NMM, open LOOT and select "load order" or whatever, and it'll suggest the correct order for your mods, then click apply or accept or whatever it is.
3. If you're going to be downloading a lot of mods, I suggest getting the mod SkyUI. It might look a little intimidating, but it's not. It changes the way the menus look and the favorites, making it more efficient. BUT BEST OF ALL (in my opinion), it gives you easy access to your different mod settings while playing the game. So if you're running around in Skyrim, you bring up the save/journal menu. In your settings, you'll now have a "Mod configuration menu" where most of your mods will be listed. So for example, if you download Frostfall mod, you'll see a Frostfall menu there. Then, you can click on Frostfall and change settings. SO MUCH EASIER. See number four.
4. If you're going to downlaod SkyUI, you MUST get the Skyrim Script Extender, known as SKSE. All you need to do, is go here
http://skse.silverlock.org/ and click "installer" and wallah. Some bigger mods require SKSE to run, so it's just nice to have it, especially if you wanna get SkyUI. After you download SKSE, you will now always open Skyrim through SKSE.
NOTE: When getting a mod, always read what it is compatible with, what it requires, etc. This can save you from making mistakes and running into problems. Like when I was trying to make the females look like what I wanted, I thoroughly read through the four female mods I listed on number 7 to make sure they were compatible. Plus a lot of mod makers will list other mods that work well with theirs.
Hope this was helpful!