building of riven shouldnt be like top up because i am new to making guides on mobafire i am not sure how to make the items correctly. the actual build should resemble:

Ruby crystal>phage>merc's/tabi>vamp sceptor>guardian>frozen>bloodthirster>counter item1>counter item2

the end build should be: Frozen, Merc's/tabi, bloodthirster, guardian, counter1, counter2

I am going to tell you now, DO NOT follow this perfectly unless the situation is exact make your own spin on the build and switch it up, my build WILL NOT work for everybody that reads this.

Riven is an amazing solo top because of her great mobility, her base hp, armor, and magic resistance. I get runes and mastries to help her armor magic resistance and attack damage in the earlier game. i get magic resistance per level runes only because you are probably not going to be fighting many ability power based champs early on in the game, and when you do the runes will compensate giving you a decent amount of magic resistance.

Be sure to have the correct mastries runes and summoner spells, talk to your team and start thinking of your counter items now.

[sub-chapter]Summoner spells
I use ignite flash and i suggest the same, but some alternatives are (for ignite) exhaust, ghost, or teleport, and (for flash) cleanse is good and really the only alternative.

Grab your ruby crystal and head up top, asking if your jungler wants a leash (if your mid wont do it you will have to). Hit the golem and walk around so your jungler doesn't have to chase it around, once your jungler is done with blue, or the golem stops hitting you, go top.

You are going to be fighting some heavy resistance, probably a fighter (such as rumble, sion, or wukong) a tank (like malphite, amumu, or nunu) or a different person (like tryndamere, blitzcrank, ect.) Depending on who you get, or how confident you feel that you can outlane them you can pick either broken wings or valor. I usually go for valor because I like the shield and extra durability. Be sure to get some decent damage down so when the time comes to get that ult off you can take them down for sure. You basically just need to keep your ground and do some damage. Remember to get wards EVERY time you go back to base, wards can win games.

[Sub-chapter] When the lane is pushed.
If your lane is pushed you can triple gank mid or go grab wolfs/golems (but be sure to ask your jungler, he or she may need it) Remember, I only suggest leaving the lane and stopping pushing if the enemy solo top is there, but isn't to keen on leaving the turret, the enemy solo top is gone, but you have no wards, or either enemy solo positions(gone or scared) and mid needs your help. Otherwise push that turret down (not completely because you may leave yourself open to ganks later[this is void if you feel confident enough to take the turret])

If the enemy is low enough on hp were you have a good shot on the kill, go for it. Your ult has a low cooldown and it does good damage. If you take the shot and get the kill or get him low enough to make him go back to base you have choices, push, or gank. Depending on how your other lanes are pushing or how they are getting pushed you can probably use your common sense and push the lane or go gank.

[Sub-chapter] If you choose to gank.
So your going to go gank mid or bot(I don't suggest going bot unless you have your boots finished) on your way make sure to ping and ask if they mid knows if wards are about, get your jungler as well, if he isn't tied up in a fight already. Jump onto that mid caster and mess him up, give him all you have to offer. Cast ignite and go balls deep for the kill. If you get the kill and the enemy top lane didn't call mia the enemy mid is going to rage, only making the game easier for your team. Successful or not, go back to lane (or base) to make sure your lane isn't going to get pushed.

[Sub-chapter] If you choose to push.
Make sure you have good warding and an escape route planned, you dont want to die and get raged at. Take that turret down. All i have o say here is, get your team that 150G and GTFO. Don't be the fool to hang around a recently taken tower.

[Note] you should be building(or have built) your guardian at this point.

Gather up that team of yours and push the turrets down, take inhibitors, get dragon, steal buffs, and gank lanes (if some noobs are still being stupid) Watch for back doors, be careful of unsuspected 'cluster****s' and watch your mini-map like its your rear-view mirror.

counter items like maw, banshee's, sunfire, and thornmail are all viable. if ad gets fed get sunfire and thornmail but if ap gets fed go maw and banshee's, obviously both can get big so you can mix them up and add some of your own.

At this point you should be able to 1v1 the main person you aimed to counter, if not that means you didn't counter correctly. Loosing or winning your build should be nearing its end and you should have about 3k hp, plenty of armor and magic resistance. Your team should be dishing the damage wile you suppress the enemies and deal some damage as well. Win or loose, say GG, be a good sport, play another game, and hope your team(or you) do better.