5- Recitation after Suratul Fatiha:

The Prophet (sallallaahu 'alaihi wa sallam) would recite another soorah after al-Faatihah, making it long sometimes, and on other occasions making it short because of travel, cough, illness or the crying of infants

Let's take two examples of short Suras you can pray with the both every prayer till you learn another Sura's

Surat Al-Ikhlas (Number 112)
A'uzu bil-llahi minash shayta nir-rajeen
This means: I seek refuge with Allaah from the Evil One, the Rejected

Bisimllah hir-rahman nir-raheem
This means: In the Name of Allaah, the Most Merciful, the Bestower of Mercy

Qul howa Allahu ahad
This means: Say : he is Allah, the only one.

Allah hus-samad
This means: Allah helps and does not need help

Lam yalid wa lam yulad
This means: He does not produce a child, and he was not born of anyone

Walam yakul-lahu kufuwan ahad
This means: There is no one equal to him


Surat An-Nas (Number 114)
A'uzu bil-llahi minash shayta nir-rajeem
This means: I seek refuge with Allaah from the Evil One, the Rejected

Bisimllah hir-rahman nir-raheem
This means: In the Name of Allaah, the Most Merciful, the Bestower of Mercy

Qul a'uzubi rab-bin nas
This means: Say : I seek refuge in the Sustainer of Mankind

Malikin nas
This means: The Owner of Mankind

Ila hin-nas
This means: Lord of Mankind

Min shar-ril waswa sil khan-nas
This means: From the evil of the sneaking whisperer

Allazi yuwaswisu fee sudu rin-nas
This means: Who whispers in the hearts of Mankind

Minal jin-nati wan-nas
This means: (Whether he be) from among jinns or mankind

Notes :

1- You have to read Sura after the Fatiha only in the first two Rak'a in the Zuhr or Asr but in Fajr,Maghrib and E'sha you just hear the Imam and you should't say it with him.

2- If you tried to memorize this two Suras but you failed .. then there is a permission to read Al-Fatiha only .. and in-Shaa-Allah your prayer is right

http://www.islamway.com/english/images/prayer/pray5.htm