tenure with employer is probably not as high on their list. If you have been 3 years in the same occupation with no lapses in between, you are probably ok. You will just have to substantiate your income with tax, paycheck, and bank records.
Most important in obtaining any type of credit is your credit score, specifically how much debt you have compared to income, and your last 2 years payment history. The better you are at those 2, the lower interest rate you will get.
I buy homes all the time. You shouldn't have a problem getting a loan as long as the property is within your budget, you manage your credit well, you can substantiate your income, and you have some reserves in a bank account (or a good 401K or IRA to use as backup funds). If you have all this, you are golden.
Take a lot of time looking around at interest rates and loan programs. Don't take the first one to come along. Also look for a lender with a local office as they tend to be more customer friendly, and easier to reach in case of a problem during your closing process.
Also, you get to pick the title company, appraiser, and inspector. Use all three when buying a home to protect yourself. Ask for references from family and friends. Do not have the lender or seller pick these for you. Also, if this is your first purchase, it is not unreasonable to hire a real estate attorney (yellow pages or Yahoo) for $250 to look over the final documents before you sign. I recently paid an attorney who found a major error in the title policy which saved me a big headache down the road. You can never be too careful.
If you have any more specific questions, send me a PM and I'll respond.