just a bit of tips
Have your passport copied for your back up, first thing to get after touchdown in DOH : buy the prepaid GSM calling card, that requires your passport copy. Later on, you can convert the prepaid into postpaid.
First day of work : meet HR, joining team and housing department. Your passport will be retained by company for residence permit application. This will take about 10-14 working days. Without passport and your Qatar residence permit, everything will be difficult, you can't buy GSM card, apply internet connection by yourself, apply credit card, etc. . .
On the same day : you will have to open a bank account, when I did mine, the bank people came to us and opened the account for us. You have to be pro active to remind them to activate your bank account. Everything was slow when I did mine.
On the same day as well : you will be offered to subscribe internet in your company accommodation. You can apply through company, provided you will stay in company accommodation at least 12 months. If you stay less than 12 months in company accommodation with internet connection installed, you will have to pay penalty to Qtel (internet and telecommunication company). To speed up the process, look for Mr. Siddique when you apply. Tell him you need internet urgently and he will tell you what to do. Or maybe new company accommodation provided with internet already, check with housing people.
You will need to rent a car for your daily activity, share with your friends is best. Just a little bit careful when driving in DOH. Traffic condition no good, people drive aggressively.
Don't bust speed limit, don't bust traffic light and don't park not in the designated parking space, fine is quite expensive here.
I hope that helps a little bit. Welcome to Doha and all the best for your training.