I hope you familiarized yourself with the vowels already, because the following symbols will be harder to memorize, especially if this is the first time you'll be encountering them. 

ㅂ     b/p (relaxed)
ㅍ     b'/p' (aspirated/with puff's of air)
ㅃ     bb/pp (hard pronounciation)

ㄷ     d/t
ㅌ     d'/t'
ㄸ     dd/tt

ㄱ     g/k
ㅋ     g'/k'
ㄲ     gg/kk

ㅈ     j/ch
ㅊ     j'/ch'
ㅉ     jj

ㅁ     m
ㅇ     ng (as ending of the syllable/letter)

ㄴ     n
ㄹ     l/r
ㅎ     h

ㅅ     s ; pronounced as sh if in the beginning of the syllable/letter
ㅆ     ss ; also pronounced as sh in the beginning of the letter

You may have noticed the symbol ㅇ should be pronounced as "ng" but that is only as the syllable ending. When used in the beginning of the letter like in 아 as in "a" for example, it is not pronounced.

The next chapter will be about combining the vowels and consonants to form a syllable.