I don't know the roundabout names but I will try to explain you as much as I can. Take E-Ring Road from Matar Street. Go straight from the first R/A (I think it is named as Parachute R/A.) Turn left from the second R/A. (I think it is named as Abu Hamour R/A.) You shall turn right from the first R/A which is very close to the petrol station. First R/A is Palm Tree R/A. Turn left from the first R/A. You will go straight till you reach the first R/A (I think it is named as Al Mamoura R/A) and make U-turn. You will come almost all the way back. Just 400-500 m before the R/A you will see Qatar Technical School. You will turn right from it and you will find QDC. When you read this I am sure it seems confusing but if you follow the directions exactly as mentioned here you will find it.
I don't know the roundabout names but I will try to explain you as much as I can. Take E-Ring Road from Matar Street. Go straight from the first R/A (I think it is named as Parachute R/A.) Turn left from the second R/A. (I think it is named as Abu Hamour R/A.) You shall turn right from the first R/A which is very close to the petrol station. First R/A is Palm Tree R/A. Turn left from the first R/A. You will go straight till you reach the first R/A (I think it is named as Al Mamoura R/A) and make U-turn. You will come almost all the way back. Just 400-500 m before the R/A you will see Qatar Technical School. You will turn right from it and you will find QDC. When you read this I am sure it seems confusing but if you follow the directions exactly as mentioned here you will find it.
Good luck.