I'm curious about being a sponsor. How long do I need to be at my job for proof of income, and how do I use my home to sponsor my spouse?
If I want to bring a foreign individual to the USA, be that a spouse or a child or a parent, or a brother, sister, etc, I have to prove that I have the means to support them. So the sponsor is financially responsible for ensuring this alien has their needs met when they arrive. The concern of the government is they don't want an alien coming here and then immediately being what they would call a ward of the state. In other words, they want to make sure the alien doesn't come over here and immediately end up on welfare or receiving any means tested benefits.
So there are guidelines that you as a sponsor have to meet. It can vary a little bit depending on your state and whether you're active duty military or not. For most people, it's 125% of the poverty level for your household size. Household size is you, the alien, and if there are any children that you're responsible for, or other dependents.
So... how long do I need to be at my job for the income to be considered solid?
There's no exact time you're supposed to have been at your job for the job to be considered viable. You need to be able to prove to the government that you have the means to support this individual financially. They are likely going to look at your work history as a whole. If you haven't worked in five years, and you've been on public benefits yourself, and now you just got a job three months ago, yes, you may have trouble. So if you've have a long history of employment, but now you've changed jobs, even if you've had some brief periods of unemployment, that's fine. Through the years if you consistently are a working person, you're probably not going to have any trouble as long as the income meets the requirements.
The second part of your question you say, "how do I use my home to sponsor my spouse?"
You can use assets as all or part of the income requirement. But that's a little tougher. For starters, you will be able to utilize 1/3 of the value of your assets towards the income requirement, not the entire thing. So if you have an asset worth $90,000, they're only going to give you credit for $30,000. Keep in mind that if you financed your house, you don't own it entirely. The value you can use towards the income is only the value after any loaned amount is subtracted. In other words, you can only claim the equity. In fact, you'll need a third-party written appraisal showing that value too. They will not take anecdotal evidence or Zillow screenshots. You need a legitimate appraisal.
One issue that may arise by using your house, in particular, is that you can't realistically sell your house, because then you've got no place to live. So it is tougher. A better alternative to using your house would be something like a 401k account or another asset that is more liquid and could easily be converted to cash. This type of asset is more attractive to them.If you are having issues with your income and are resorting to assets, it may be a smart idea to utilize a joint sponsor who is legally residing in the US over the age of 18 who has a solid income and is willing to joint sponsor for you.