So I had an outlet that was sparking and sometimes cutting out (till I moved it to an angle) so I decided to change it. Turned the breaker off, replaced it, turned it back on and find out my room and a few other things on my side of the house don't have power. Now this had happened before with my bathroom on the same circuit so I know what breaker it is. So a few outlets on the way from the breaker box (on the same breaker as my room) to my room work, and stop about halfway through. I bought a multimeter and tested my outlet and get ~120 Volts. Tested a light switch (that wasn't working but on the same breaker) and same thing, so I'm at a loss of what to do. Any help would be appreciated.
What I'd do is first systematically correct all the receptacles in one circuit, then examine the switches for the light fixtures and insure that the switches are in the hot line and not in the neutral. This means that each 1-pole switch should have an always hot on one contact and switched hot on the other. Note that a white colored wire can be and often is used as a hot or switched hot in a loop for a light.
I hope this won't happen but it could be that if you correct a receptacle and turn the breaker on, it will trip because incorrect wiring in either a remaining receptacle or in a loop for a light makes a short. If that happens you will have to correct all the remaining wiring before proceeding, instead of going receptacle by receptacle, switch by switch, light by light.
Finally, after all the receptacles and switches have been corrected move up to the light fixtures and insure that the switched hot goes to the proper wire lead or contact. In a screw base fixture this means the central contact is switched hot and the neutral. In others generally the switched hot lead will be black. Note that a white wire could be used for a switched hot so you could be connecting a white wire to a black wire (something you would usually not do with receptacles).