I've been into clustering  ( '94 '95 )for almost as long as I've been into rocketry ( '92 '93 ).

The first cluster that I can remember doing was a scratch built Estes size rocket with 3 C motors in it ; with a little help from a relative I was able to get all three motors to light . I wasn't hooked on clustering just yet though , that happened a year or two later after I certified level 1 & bought my first timer from Adept ( PST 611 ) which I used in  my first air start ( H 180 to 2 F 80 ) From that time on I was hooked . I have flown everything from 2 D rocket all the way up to a cluster/ stage 3-I's to an I 284 .

If you are just starting out : Go with a basic cluster of 2 or 3 motors or an Estes 2 stage rocket is also a good starting point ;

After a few flights you can try something bigger .....

I find too many people trying things before they can fully understand the concept & just mimic what others are doing .

I believe : If you can't explain what you are doing to someone else , than you shouldn't be doing it in the first place .