I've written a few guides that might be of use to you, most of them are now up on the FTB Wiki as starter guides, so I'd suggest it as a good starting point. In brief:
Tinker's Construct: It's tools, Jim, but not as you know them. It introduces an entirely new tool crafting mechanic using multiple stations and a staggering variety of materials to make things with. Ever wanted to use something other than wood for a tool handle? Now you can. Also included is new sorts of tools. It's pretty well documented in game with books that show up when you spawn in. Honestly, I am of the personal opinion that this is how tool construction should be done in vanilla.
Team CoFH has a suite of mods they have produced to bring you into the industrial age. The 'core mods', CoFH Core and Thermal Foundation, don't do much on the end-user side, but they give mod pack developers the tools they need to make everything interlock and interweave on the back end. Thermal Expansion introduces a power system called 'Redstone Flux' that has become a staple for many (though by no means all) tech mods. There are dynamos for generating power, and machines that require power to run. These machines have a variety of uses, which are fairly well documented. Thermal Dynamics is where you will find the conduits and ducts to automate moving things from Point A to Point B. There's also a suite of servos, retrievers, and filters to make things even more interesting.
Minefactory Reloaded. Technically in the TeamCoFH group, but it's being handled mostly by Skyboy. Ever wanted to automate a tree farm, the growing and harvesting of your food, or the breeding and slaughtering of cows for leather? Ever wanted to automate sheep shearing and chicken egg harvesting? Now you can do that. It brings a whole new dynamic to the term 'renewable resources'. Oh, and Rednet Cables puts your old redstone wiring to shame.
Thaumcraft 4 is the quintessential 'magic' mod that I have come to love. You have a lot of research to do to really get involved in the mod, but there's always a new carrot dangling juuuuust out of reach to give you the desire to go out and Scan All The Things.
Chisel is a mod which brings a ton of new textures for most building blocks. Let your creativity run wild with the possibilities! Also introduces Marble.
Carpenter's Blocks create a radical dynamic to construction. Rather than creating specific types of blocks, it creates a shell for block shapes that are then able to have nearly any material applied to them! Want glass staircases? You can do that. How about a thatched sloped roof? Easy-peasy. How about a hexagonal wall? Got ya covered. Slopes, staircases, doors, beds, pressure plates... they don't just add static decoration pieces, they add the foundation upon which can rest any material you care to construct in!
Having trouble remembering all these new recipes? Well, There's A Mod For That(tm). It's called NEI, and is considered by most to be a staple mod. In brief, it is a searchable database of every single recipe available to you. Addons bring additional functionality to the mod by adding various machine-centric recipes to the mix. You can also look at what recipes use an item as a material, or what items are used to make that thing.
Wanting to store more items? There's a mod called Iron Chests that makes more expensive chests that have more inventory slots. A single iron chest stores as much as a double chest does, although it does take iron to make. There's also gold chests and diamond chests for even more storage.
With these, and maybe some utilities like a minimap, Inventory Tweaks to make sorting your stuff a snap, and a few other odds and sods, you have a pretty solid lite mod pack. Some other options for the more adventurous:
Botania. Ever wanted to be a long haired hippy freak who gets along by using flower power? Now you can do that. Also, you can protect your lawn from zombie invasion by using flowers to defend it. Gee... I could've sworn I'd heard that somewhere else...
Blood Magic. Ever wanted to go the other route and be that creepy emo sort of magic user? Look no further! Not recommended for all ages, but if you aren't squicked out by the concept of working magic by sacrificing blood at an altar, it's quite interesting.
EnderIO. Once you start playing around with ducts from Thermal Dynamics, you'll soon wish you could run multiple types of ducts in the same square to make things more compact. EnderIO has your back with Conduits. Not as pretty or shiny as ducts, but you can run multiple types of ducts in the same block. And block facades can be painted to look like almost anything. Oh, there's some other things this tech-heavy mod does, but conduits are my personal favorite.
Mekanism. Bringing your production to the corporate scale. Ever wanted to process more than one item at a time per machine? How about seven at a time? It isn't cheap, but it can be done. Also, extremely efficient ore processing can be found here, although the infrastructure required for the higher tiers of efficiency are fairly complex and interconnected.
Hunger Overhaul, Pam's Harvestcraft, and Agricraft are three mods I want to mention in the same sentence because they go together so very well. Ever thought that vanilla food was boring? Getting tired of living on baked potatoes? Hunger Overhaul swings a pretty hefty nerf bat at food values, and provides some additional tweaks to the hunger mechanics that I personally feel should be vanilla. Pam's Harvestcraft has a TON of fruits and vegetables added to worldgen that can be used to produce hundreds, if not thousands, of different food items. Open up your own fast food restaurant chain! Some of the more complex recipes produce foods that, even with Hunger Overhaul, are quite satisfying. And last, but by no means least, is Agricraft, which brings the concept of cross-breeding to produce better strains of crops. We are entirely GMO-free here, but we are growing stronger, more rapidly growing, and more productive plants. Also, an irrigation system which can further speed up your plants production. The combination of these mods makes for a much more interesting and robust food mechanic.
ExtraUtils is... pretty much what it says on the tin: a bunch of miscellaneous utilities that are generally useful. Possibly also paired with OpenBlocks and RandomThings, these mods are the garnish that makes a pack more interesting.
Barrels were originally introduced in a mod called Factorization back in... I think it was 1.3ish. However, the mod itself received an overall lukewarm reception. It is still around, I think, but many wanted barrels without having to have the whole mod installed. For those people, there is a mod called JABBA (Just Another Better Barrel Addon). Barrels can only store one type of item, so a barrel with cobblestone can only hold cobblestone, it won't be able to also hold wood or even smooth stone. However, it can store sixty four STACKS of that one item at a time. Then you can get into the upgrades for even more fun.
If that's not enough, there's Applied Energistics 2. In brief, it's matter-energy conversion that lets you store stuff on disk. Expensive in terms of components required to make even a small storage system, but it can store a truly stupendous amount of stuff in a small space, and interconnect a lot of automation as well.
Anyway, that's the highlights, I've written guides for most of these mods, so you can probably find them either on these forums or on the wiki. It should at least get you started.