The Mental Health Association of Prince George's County is seeking volunteers to serve as telephone crisis counselors for the Prince George's County hotline.

No experience is necessary, and training is free. Teen-agers, students and senior citizens are welcome, the association said. Shifts are available during the daytime, evening and weekends. Training begins April 29. Call 577-3140 to request an application. Historical Trust Matching Grants

The Maryland Historical Trust, a division of the state Department of Economic and Community Development, is accepting applications for matching grants-in-aid for survey and planning projects.

The grants range from $1,000 to $25,000 and are offered to local and regional governments; nonprofit, tax-exempt organizations; educational institutions, and individuals. Grant recipients must match the grant amount.

Funding is expected to be available after Oct. 1. Applications must be postmarked no later than June 1. For application forms or more information, call 269-2438 or write 21 State Circle, Annapolis 21401.

The trust is also accepting applications for state capital grants for historic preservation projects in the fiscal year beginning July 1, 1987. Local governments, nonprofit organizations and individuals are eligible to apply. Projects must be listed in or eligible for listing in the Maryland Inventory of Historical Sites. The average grant is $30,000.