There airlines and cruise lines that offer plenty of senior discounts. You can also try contacting travel agencies for more information on how you can get a good deal on a travel package near you.
To find cheap travel, look for package deals, such as a theme park package that would include park and hotel accommodations. You can ask if you can use flyer miles, go off season, when rates are more reasonable. Ask if they have special rates for seniors, or a manager's special for example. Compare rates through a travel agency or through searching online.
Orbitz is a good website to book online travel for seniors. They also have good discount rates.
Check out different travel agencies to find the best discount, I'm pretty sure there is a discount on most things that seniors do. If you can't find a good enough deal you may be able to talk through someone who works at a seniors home and they may be able to sneak you through some loop holes.
Single seniors who like to travel now that they are retired and who want the company of other seniors for safety and social reasons can try looking at seniortravel.com for many ideas.
Where you travel depends on your abilities and what you want to do. There are special travel plans for seniors with different activity levels and needs, and talking to a travel agent may help you find one that's right for you. There's also information available here on different options: www.suddenlysenior.com/TRAVELPAGE.html
There are several websites that gives off good travel packages in general. This website, www.seniortravelhub.com/senior-travel-deals/travel-packages, is geared specifically towards seniors.
You can find several deals for seniors traveling to Las Vegas. You should contact your local travel agent. They can be able to help you with group deals.
Travel insurance is always a good idea whether you are a senior citizen or not. You can find information on insurance for seniors here: http://www.travelinsurancereview.net/senior-citizen-travel-insurance/
You can find inexpensive senior travel if you contact AARP. They cater to seniors and would be able to find you good deals. You would need to join them for a yearly fee.
If your grandma wants to travel the best thing is to find out what is her favorite travel destination before you book her on the wrong vacation. You can check out priceline.com.
Go to your local travel agency and speak to a travel agent about senior travel packages. They will give you all the information you need about the available packages.
According to research travel insurance for seniors is hard to find. The following website provides good info. http://www.usaflightinsurance.com/articles/insurance/travel-insurance-for-seniors.htm