The cost of living in Switzerland is among the highest in the world, especially in Zurich and Geneva. Accommodation especially is exceptionally pricey, and demand is also high for the places that are available. You'll need to count on earning a fairly large amount to cover costs each month. For more information on specific pricing I suggest you have a look at the Cost of Living in Zurich page.
You will need to apply for a residence permit, which allows you to both live and work in Switzerland. It's quite difficult for someone from a non-EU state to get a residence permit, however. The first step will be to secure a job so your employer can apply on your behalf. The downside is many companies don't like to hire people who aren't EU citizens and already living in Switzerland with a residence permit - so I'm afraid it's a bit of a Catch-22. For more details I suggest you read Visas for Switzerland. Good luck!
Are you still moving to Zurich? I suggest you get in contact with the Indian Association of Greater Zurich (www.iagz.ch) - a group for Indian expats living and working in Zurich. They should be able to tell you where the popular Indian areas are.
You will need to first apply at the institution of your choice to get a provisional acceptance and then apply for a visa the Swiss embassy in Abuja. You can check with them what documentation you require, but you will probably need to provide proof of acceptance, proof that you have enough funds for the duration of your studies and an affidavit that you will return to Nigeria when you're finished with your studies.
The fees will depend on the institution. For example, a 1.5 year MSc at the Swiss Textile College will cost CHF 15,300.
Whether your salary will be enough depends on your lifestyle. I suggest you make a list of what your averages purchases are in a month and then have a look at the Cost of Living in Switzerland page for more info on prices. Also have a look at Accommodation in Switzerland for more information on what you can expect to pay to rent an apartment.
For the B2 language certificate, I would imagine that as long as you obtained the certificate from an accredited institute it wouldn't make much of a difference whether you did that inside or outside of Switzerland.
With regards to your questions about work and residency - what nationality are you and your husband? You can only apply for a residence permit once you have secured a job, and you may not work without having obtained a residence permit. The likelihood of obtaining a job and a permit both depend on whether you are an EU/EFTA national. If you are, you are much more likely to succeed. You can read more on our Visas for Switzerland and Working in Switzerland pages.
A general tip: in future, try to post forum questions as a new topic rather than as a comment on an existing forum question as you've done here; that way you're much more likely to receive a wider range of responses and advice, possibly from locals or fellow expats in the country.
Best of luck.