Since there's a lot of new players on the board I figured I'd write a quick intro to smite (conquest at least for now), at least for the roles (mid and jungle) that I tend to play a lot of.
If you're jungling, you buy bumbas, power potion and hog1 for every god unless you're someone with really good natural jungle sustain (ie thanatos). There's only a couple gods that can open w/o bumbas. Thanatos is one for sure; who the others are I'm not sure. You start with whatever side the solo starts on. If you start right side, solo red buff then go straight to blue buff.
If you start left side, you have opportunity for a very nice gank at level 3 if solo laner has hog (phys almost always do, mages sometimes don't). You hog speed, go blue, hog that, go straight to their blue. If your lane clear isn't bad and/or theirs isn't excellent, you'll get there as they're fighting blue or sometimes earlier. Very often you can get surprise ganks with this and/or steal their blue. This can set them back horrendously if you pull it off. If you get a double kill it's practically gg right there. Stay in lane either till like 1:30 so you can do back harpies or a bit later if you wanna skip them and get lane exp. Either works.
Either way, you need to be at mid harpies for their spawn. They spawn every 2 minutes (changed recently I think?) so they're up at 2:15. It might be 2:30 now, haven't played conq in a little bite. Contesting mid furies every 2 minutes is your most important job by far and must be done above almost anything else until late game. Mid harps are more important than ganks.
Other than that, take down the blue buffs for your teammates. Never take the buff. Get ganks off as much as you can, especially in mid/duo, but don't sacrifice a mid harps rotations for them unless it's going to be a big play. Obviously make sure you're clearing your own red/speed buff. Some people give their mid the red. This is very generous and can help significantly (especially in early game where lane clear wars are so important in mid).
If you're mid your opening build is a lot more open. It mostly depends on the god. Polynomicon is a good first pick, as are boots, doom orb, book of thoth, etc. You start at right side mid camps and go straight to lane after. Pick a god that has excellent lane clear (99% of the time a mage). Ideally they should either do excellent damage or have some sort of utility that's very useful in team fights. Some gods have both to varying degrees (ie Ra). Your play also revolves around contesting mid camps. In a perfect world your jungle and/or support will take them for you and you can get xp at the wall, but competent teams should be contesting them.
Beyond that you primarily just need to farm, as safely as you possibly can. For the first 15 minutes of the game at least, you're going to be sitting your lane or contesting mid camps 90% of your time. As long as you can get your lane farm in safely and get some mid camp kills, and not dying, you're doing your job. If you can get some kills along the way that's nice too, but don't risk getting yourself killed. You need that farm and dying costs you a lot. Mids are usually a bit weak game but VERRRY strong late game. There are some exceptions but that's usually how it plays. You just need to safely get to late game build as fast as you can and you'll dominate shit.
I very rarely play adc, sup or (physical) solo so can't speak in much depth about them.
I play a TON of Ao Kuang, Freya, Poseidon, Ra, and Thanatos if anyone has any specific questions about them.