It's not that hard:
Anywhere you go you should be finding ores, soulgems, plants, and of course armour/weapons/jewelry all of it will let you level up fast, an example:
2 iron ore get converted into 1 silver ore, 2 silver ore into 1 gold ore iirc. then you smelt gold into actual bars. Every time you cast the spell you are leveling up one of your magicka. You can make then silver or gold rings (leveling smithing) and sell them (leveling speech), or first go to a enchanting station and use a soul gem to put an enchantment on it leveling that then sell it.
Smithing you can level up to max in almost no time just by buying/finding hide/leather and iron cheap and making the basic stuff and selling them. You can also level Alchemy up super fast. Just go around to the alchemy stores and buy up their supplies of ingredients and experiment with creating potions (or look up online what will make uou the most if you're like i was) and you can spam it like nuts, get to legendary, then start all over. I leveled Alchemy and BLock up to 100 and back more times than i can remember.
Block is another one you can spam btw. Just find a wolf or a mud-crab somewhere where there are no other creatures and if you have a shield ora 2handed weapon block where your back is against a wall or something like that. They'll keep coming at you but cant get past your block. I'd read a book while holding the block button.
None of this is essential you can probably level up without grinding but I enjoyed it because it let me explore the world a lot. A few recommendation I would make though:
Save the main storylines (The dragon and civil war) for as long as possible. The real joy of the game is the side story. I don't ever even start the Civil War until I am forced to until I need to forward the storyline (not because its bad).
Talk to everyone, and don't just stick to the main roads or fast travel with the carriages. You have to explore everything and back track because the game is crammed with hidden shit that isnt even on the official in game map. I've found stuff on replay that I didn't find after 300 hours of play.
Smithing and enchanting are worth level up fully because you can make more powerful equipment then you will ever be able to buy or find. I've been able to craft some shit that is almost game breakingly awesome.
The DLC is really fun if you like the game. Hearthfire lets you build your own mansions, adopt kids, etc and its perfect for people like me who like to get lost in world building shit. Dawnguard adds Vampire quest stuff and can make the early game harder with the random vampire attacks but has some fun missions and really good added weapons. Dragonborn is the best though because you can ride Dragons. You also get a ton of new Shouts, some cool new powers (the option to not harm your followers with your own attacks anymore was useful to me as a runaway train), and a lot of cool adventuring.
you can plot out how high you need to level up to make your ideal character with this http://ca.ign.com/wikis/the-elder-scrolls-5-skyrim/Skill_Builder