If I manage to get an expert spellbook while being novice, can I stil learn it?

Transmute goes great with the mod that adds Electro-mining (mining beam) and Liquifaction (Smelt anywhere).

DanmakuGrazer's answer is correct, but there's a little more to it than that. You can learn any spell for which you possess the book. Your limiting factors in Skyrim aren't tied to your skill so much as your level. For instance, if you find a Master level book for the spell Infinite Lollerskates (no, it isn't real) when you are level 2, you probably can't cast it due to your Magicka being insufficient.

You certainly won't be able to buy it instead of loot it, either; the leveled lists for merchants are designed to scale the spellbooks with your potential spellcasting level. That's why you get a fistful of novice books from the Riverwood trader your first run through, but later on they have a book of Epic Kaboom for sale.

It's also worth noting that the spells in Skyrim do presume the use of enchanted items the higher your casting levels get. Try casting a Master-level Destruction spell while in your skivvies to see how quickly your Magicka drains. That worth both ways, though. If you can get an enchanted helmet/circlet, boots, armor, gloves/bracers/gauntlets, ring, and necklace together which combine to an 85-100% discount on a spell of a given type, you can cast Master level spells out of that school very early on.

Just be aware that this is game-breaking if you have mods that unlock disenchanting on the Archmage Robes. They pack an enchantment called Skein of Magnus which ends up making all of your spells free if you stack it on other armor.