First time kata bhetyo, k garyo, explain scenario, some details about the companies u had.
When u got engaged, where, who proposed. 
Each other's family members details, like name, what's going on, how often do you talk to them, what do talked about last when u had a conversation with them last time, what do you call them.
Each other's job, or what they do.
Details about the house you both living in.
It's good to keep the details about everything.
Prepare for being interviewed separately!!!

it should be simple ,just take everything you can provide them ,like photos of places you went together ,bank a/cs ,bills ,expenseses that you have accounts together,jobs, both of yours family background ,family members , you can even prepare the file in power point (scan and put them in ppt) and also carry originals in seperate files. it will be simple .

kancho bro, i-130 ra i-148 file garda .. supporting documents haru teti kherai mail garne ho ki pachi magcha... kasari file garne ho.. please ali kati sujhau chaiyo yaar malai ni... i would really appreciate if you could share your experience...

 Thank you Default061 and Fantush Bro.
@Alche- I sent all forms, medical checkup, and financial support documents at once. I think your process speeds up if you send all those documents at once. I had applied in mid Jan. and got my EAD already and have interview in next month. 

I have seen one of the website:
They might ask who turn off the light last night?
Who throw the trash last time?
You might put in seperate and ask bed location, window location, closet location in your bed room?
Same way rest room and kitchen ko environment?

Nepali_Kachoo bro, once you submit all the document, will you first get call for finger print and you will get EAD ani interview ho?