This is my first Build Attempt , So im not going to make a huge Text About the Build that i just made.
First of All , what i buy in the beggining of them game is Doran Shield.
Then after level 6 withouth dieng, lol, U should buy mercury treads and if u have some gold left of the farm u just made so far buy Giant's Belt , To make you more hard to kill .
Then U should go for Warmogs Armor , next Randuin's Omen , Guardian Angel , Atmas Impaler , but first of all i forgot to mention , u should sell your doran shield , when u completed your Randuin's Omen , And buy 2 Sunfire Cape's.
This is my regular build , against a team of most of them as Dps or Fighters.
If your enemy team has more Magic damage than attack damage u should buy instead of Randuin's Omen , Force of nature.
For Summoner Spell's i choose Flash and Exhaust , but u can always change the Exhaust for Heal or maybe Cleanse.