It’s summer party season, and you’re thinking of inviting a couple of dozen friends for a sit-down dinner. Or 200 for a backyard blowout saluting your 90-year-old granny. Or just a few (read: 50) folks to a wedding at your home. And you’re thinking you need help.

Smart move.

You can hire a caterer to handle everything from appetizers to cleanup, or tap a restaurant or grocer to provide some of the food. Those decisions can affect the price tag, from a hundred or so dollars into the thousands.

Experts say you need to have a plan, especially when working with a caterer.

First, “Be sure you know how much you want to spend and how many people will be there,” says Steve Westphal, a restaurateur in St. Petersburg, Fla.

Then be ready to talk specifics.

“Be upfront about your wishes, including the style of food you like, the style of service you expect and the price that you would like to pay,” says Simon Powles, head of Stephen STARR Events, a catering division of Philadelphia-based STARR Restaurants, a group that includes Buddakan (Philadelphia, New York, Atlantic City) and Steak 954 in Fort Lauderdale, Fla.

Also, if you need a full-service caterer, “Make sure that they can handle all of your needs: staffing, rentals, coordinating with other vendors,” Powles says. In addition to providing full-service catering, many caterers offer a quick-service option, which provides, say, a few dozen hors d’oeuvres, desserts or servers.

Which prompts the question: Shouldn’t I just hold the event in a restaurant?

“A restaurant is a great place to host a special event,” Powles says. “But hosting an event in your home or chosen special venue is much more intimate and will allow you to customize the space to reflect your personal tastes and preferences.”

More tips from the pros:

Before choosing a caterer, ask for references.

Tell the caterer about any special dietary concerns (nuts, seafood, etc.) and party theme, Westphal says.

Give notice if you want to use your own china, or have them provide a favorite beverage or cake, etc. “This allows the caterers to write you the most comprehensive proposal that they can for your specific event,” Powles says.

Good caterers always bring what they need. “Our golden rule: You never go into a client’s cabinet to get a utensil or bowl,” he says. “We always have someone on call so they can bring us what we need.”

Caterers need a work space, somewhere to prepare the food and arrange it on serving platters. “If we’re given the option of the client’s kitchen or the garage, we take the garage. There’s less impact on the home,” Powles says.