Which ever type you choose, make sure the feed station and the top of the metal tube and metal connections. Squirrels will chew through the cheap, all plastic feeders in a short time, and you've wasted your money. A feeder will quality for years.
If you have a connection that is not a mechanical way to beat the squirrel, how do you connect a key to prevent theft of food. If your feeder on a pole or post, metal or plastic guard to keep squirrels squirrels and even raccoons from climbing the post. Also keep a coat of plastic on the squirrel feeder hanging from above.
What should I feed wild birds? Various bird food available at grocery stores and specialized birds extraordinary. Are wild birds prefer butter, meal worms, sunflower seeds, peanuts or a blend of luxury? There is no single answer, but in general the type of food will determine the birds appear in your feeder.