Welcome to my first guide.
1st I am sorry for my bad english, becouse I am from Czech Republic.
2nd I am still testing this play style for this champ, so I will ubdate it after future.
Solo top Nida as I play her is surv AD dmg dealer.

Pros:
1st: Ranged
2nd: Mobility Aspect Of The Cougar+ Prowl+ Bushwhack / Pounce
3rd: "Free wards" Bushwhack / Pounce makes you realy hard to gank for opponent junglers

Cons:
1st: No CC!
2nd: You are weak before ulti. Aspect Of The Cougar
3rd: Javelin Toss / Takedown is awsome stealing mechanizm (like Garen´s ulti Demacian Justice) don't use it to steal kills, when you dont need. (Your team will not like much stealing....)

I guess you ask why those runes?
Answer is here=

Greater Mark of Attack Damage + Greater Quintessence of Attack Damage = helps me last hit and farm.

Greater Seal of Scaling Health = I got these runes on other champ, and I dont want to buy new runes so I try them and they arent that much bad...

Greater Glyph of Scaling Magic Resist = I focus on armor and hp at the beggining of my build so these runes help me to survive against magic damage dealers.

I starts with Cloth Armor and 5x Health Potion, this combination helps me to survive. But sometime I prefer combination of 3x Health Potion and 2x Mana Potion.
On solo top try to focus on farm, and with your spear (auto attack and Javelin Toss) keep your opponent from you and minion. Remember you are ranged, dont forget to use it.
Wriggle's Lantern and Mercury's Treads combination gives you Tenacity, Armor, Magic Resist and as a bonus Sight Ward.
After these two items you focus on health Frozen Mallet gives you a lot of it.
After health you will need some armor Glacial Shroud will help you, and as a bonus some mana and CD reduction.
Now you need some dmg. Iceborn Gauntlet will use Glacial Shroud and gives you some damage and mass slow.
Now you can think about Hexdrinker and Atma's Impaler (At almost every game I end by now....)

Passiv:
Prowl
It's more powerfull then you think. EVERY TIME YOU RUN AWAY RUN THROUGH BRUSH!
Q:
Javelin Toss / Takedown
Javelin toss can do a lot of damage without any Ability power, when is clever used.
Takedown everyone know how to use Garen's ulti Demacian Justice, its same= lower hp, better dmg, and what is more it proc with lifesteal ;)
W:
Bushwhack / Pounce
Bushwhack this traps are very usefull= you don't need many wards.
Pounce everyone hates this spell, everyone! You simply jump forward and deals damage, low CD makes it awsome running mechanizm.
E:
Primal Surge / Swipe
Primal Surge its a heal that gives you attack speed buff, for ad nida is often used to gain Attack speed.
Swipe you deal magic damage in front of you. Not much damage, but not low.
R:
Aspect Of The Cougar
You change form that gives you Armor, Magic resist and movement speed. And change your abilities.