you get a few uu, turns and a protection when you first get ss then after that you can send uu,turns and credits to other people. the market resets on either sunday or monday i think its monday thougth.
what i did when i got ss was trade 1000 ish uu for 1000 ish turns then with these turns i farmed until i had 280 mil(which was my bank limit) then i traded these for another 1000 ish turns and 1000 ish uu, thus getting my original 1000 back but now i had about 1300 turns then i farmed again and brought more turns then farmed and spent the money on building up my power.
now i buy as many turns as i can throuth farming then after i have used my 3 trades i use the credits i get from farming on my up ect