First congrats on the job. I once upon a time thought I had a great deal, also right out of college. I ended up slaving for 6 years getting the "top performance raise" of 1.5% per year. In the end, my 'cherry' deal started going to hell, I was working 90 + hours a week, titled as hourly, but getting paid as if I were salary. When they told me thier bottom line was more important that the birth of my kid, I told them where exactly they could fuck off to. Not trying to stress you, just be sure to keep your options open, don't be afraid to 'hire' yourself into a raise and make that 40K into 45 -50K after a couple of years experience in the field. Also hold off on that Beemer, make some money, save some money, and make sure you're solid. Depending on where you live, 40K isn't really all that much, but it'll buy a decent Chevy car.
As far as the drug test, sounds like they're serious about that shit. I was working for a company that specialized in security for the federal government, they too had random pisses. I didn't smoke until my last year there, but once I had it with their bull shit, I hoped they'd fire me (saddly they didn't.) Anyway, get some 'at home' tests for $20 at the pharmacy. They're private and instant. Once you no longer register on them, then I would take the $40 lab test to see the results. Also if they do folicular testing, I'd go to a head shop and get the shampoo that's supposed to wash out THC, I have no idea if it works or not, but it's a CYA.
I don't want to be a kill joy, I hope you have a great time at your new job and they're not flaming assholes likes I worked for. I opted to go back to college and get an advanced degree or 3 (2 maters and hopefuly a Doc.) Then I plan on being really educated and unemployed.
The good side, no-body pisses students, I'm smoking almost 1/4oz a week on slow weeks and up to a half when I've got supply, I also am showing up to class wasted and still pulling A's. IMO piss tests are just another form of corporate control of the American people, and they have no bearing on a persons ability to perform their tasks at work, in fact I work BETTER high. As I result I shall never take one again, but then again I passed them for 15 years after I got out of college without any detox at all, now it's my time to play and stop giving shit about keeping up. Then again, I also carried my wife for years, it's her turn to be the bread winner.
-RT