i didnt know the answer to these questions so i googled and from what i can work out, the difference between e12 and other e series is the manafacturing tolerance percentage.
E12 is a 10% tolerance band series of resistors.
e12 is so called because there are 12 values spaced exponentially across a 10 times resistance change. eg between 1k and 10k there are 12 values of resistor in the e12 series. The actual value of any resistor could therefore be within 10%.
See link about standard eia resistor values
Resistor Values E6 E12 E24 E48 E96 E192

apparantly 5 bands are used both for more precise resistors where a 3rd value is required e.g 2.34k but more likely i would assume on your resistor as an indication of the temperature coefficeint. The link below has a table with temp coefficent colours on.

Resistor Color Chart

Get yourself a multimeter and you can measure the resitance of your resistors to see what they are.

I don't know how in depth a gcse textbook goes but i too am trying to learn electronics and i'm using a textbook called 'the art of electronics' by horowitz and hill. I highly recommend it.

***my 100th post***

firstly gratz on 100th post
second thanks for answers i think i got the answers i needed
E12 being 10% and reason i was confused is that the pack of resistorsi bought E3 had 16 values with gold band 5% tollerance and the e12 pack i got was also gold band 5% both packagaing had 1/4 watt 5% labelled next to the E3 E12 , just in E12 there was more resistor values in it. but judging by the link you gave me E3 is being discontinued so maybe E 12 is a combination or old and new? i dunno as for the 5 band problem i get what ya saying it makes sense just maybe theresistors i got were poorly printed.

Thanks for replys though

Just realised also E12 like you say is 10% tollerance so therefore should have final silver band? packageing says they are e12 5% so does that mean that the whole Series E12 or what ever can have difrent tollerances so again why the difrent series LOL bah...