Just started the show on Netflix last week, am currently near the end of Season 2. Now I won't come back to this thread because I don't want to spoil anything for myself. 
Usually the big stuff will be in spoiler tags, such as episode recap for those that missed it:
Spoiler, click to toggle visibilty
- Madrigal becomes target for poilice investigation
- Walt hides the ricin cigarette, and makes Jesse find a fake to think misplaced it
- Merkert is no longer the head of the DEA due to his relation with Gus
- Sklyer is still in shock and refuses to face or talk to Walt
- Walt & Jesse offer Mike a partnership, he refuses
- Mike is interviewed by the DEA, where he learns of Gus's offshore bank account and $2 million in his granddaughter's name, which has been confiscated by the DEA
- Mike meets with Lydia, an executive from Madrigal, who tells Mike to kill his own men before they speak to the DEA. Mike refuses.
- Walt & Jesse meet with Saul to find new location for them to cook
- Jesse rounds up every chemical except methylamine
- Lydia puts a hit out on Mike for $30,000 and $10,000 for each of Mike's men on Gus's payroll.
- Chris kills Chow (asian guy Mike rescues in Season 3) as a trap to get Mike, Mike kills Chris and learns of Lydia's plot
- Mike holds Lydia at gunpoint in her home, but spares her life after she agrees to provide Mike with methylamine
- Mike calls Walt to tell him he reconsidered his proposal
