Rules of Tajweed in Quran

1. There are 4 Tajweed rules you have to follow whenever you find Noon-sáakin نْ ) or Tanween signs ( double zobor/fataha ( ً  ), double zer/kasara ( ٍ  ), double pesh/damma ( ٌ  ).

These rules are known as Izhar(clear), Iqlab(change), Idgham(merge) and Ikhfa(hide/conceal).

Tajweed rules means how much effect you make on Noon-sáakin or Tanween character while reciting Quran. For example, in Iqlab noon-sáakin or tanween character must be completely changed to meen sound while in izhar Noon-sáakin or Tanween has no effect and need to clearly pronounce them. In Idgham Noon-sáakin or Tanween character is completely merged with the following character making as if there is no Noon-sáakin or Tanween character exist. In ikhfa Noon-sáakin or Tanween is concealed/hidden

(a) Izhar means clear and there are 6 letters namely (hamzá ء,  ha ه,  ain ع,  há ح,  ghain غ,  khá خ). There are no gunnah(nasal sound) when Noon-sáakin or Tanween follow these letters. 
(b) Iqlab means change and there are only one letter which is (Ba ب). Noon-sáakin should be replaced with Meem م and must do full gunnah. 
(c) Idgham means merge and there are two kinds, one with gunnah and, the other without gunnah. The 1st one has 4 letters namely (ya ى , meen م , wa و, noon ن) which needs full gunnah. The 2nd one has 2 letters namely (Ra ر and Lam ل) and there should be no gunnah. 
(d) The last one is Ikhfa meaning conceal or hide and it has 15 letters namely (ta ت, tsa ث, jim ج, dal د, dzal ذ , za ز, sin س, shin ش, swad ص, zwad ض, twa ط, zwa ظ, fa ف, qaf ق, kaf ك) which need light gunnah.

2. There are 3 other Tajweed rules whenever you find Meem-sáakin.
    (a) The 1st one means Ikhfa shafwi and the letter is (Ba ب) which need light gunnah. 
    (b) The 2nd one means Idgham mislain e sogir and the letter is (Meem م) which need full gunnah.
    (c) The 3rd one means Izhar Shafwi and these includes all letters except Ba and Meem above and has no gunnah.

3. There are Waajib Gunnah whenever you find (Shadda on Noon ّن ) or (Shadda on Meen  ّم ) and you need to read with full gunnah.

4. There are kalkala letters known as shadow letters which creates echo sounds. These letters are (qaf ق , twa ط , ba ب , jim ج, dal د ) (in total 5 letters).

5. There are 3 types of Mad letters namely (alif ا, waw و  and ya ى ). When these letters come you need to elongate the sound like aa, wuu, yii). These are called Mad Asóli. Sometimes           these letters are shown as standing Zobor, standing Zer, ultha Pesh). These Mad are always one alif long. You can find also long tilda which need more longer sounds like 2 to 5 alif long. 

6. There are Ra ر sound either with full mouth or empty mouth. Zobor or Pesh on Ra make full mouth while Zer makes empty mouth. If Ra has sukun then you need to look the letter before, if         Zobor or Pesh then these should be with full mouth otherwise empty mouth. If Ra has Shadda with Zobor or Shadda with Pesh then full mouth and if Shadda Zer
    then empty mouth. 

7. Allah الله should be with full mouth if Alif has Zobor or Pesh and if Zer then empty mouth.