Everyone is a coin dev. these days.
But you're still doing it wrong.
If you aren't changing the message starting string, don't even compile your coin.
When ever you make a new coin in this example a Litecoin clone, open up main.cpp and search for pchmessagestart and you will find this:
unsigned char pchMessageStart[4] = { 0xfb, 0xc0, 0xb6, 0xdb }; // Litecoin: increase each by adding 2 to bitcoin's value.
CHANGE THE LAST TWO HEX BITS ON EACH AFTER 0x OR YOUR COIN WILL SUCK ASS AND FORK WITH OTHER COINS!
Make sure they don't match up with another coin.
Have a good day.
Thank me later.