The two fundamental meanings of the English word actual have to do with whether you mean something is real as in not fake or artificial, or whether you mean something is current, as in happening in the present, or up to date.
First, it often helps English speakers to remember that the Spanish adjective actual does not mean "real" but "current." The noun actualidades means current events, as in the news. It's even a section in the newspaper and a segment of broadcast news programs. If you can remember that, you may avoid the incorrect use of actual.
Consider these examples:
El director actual se llama Geraldo (The current/present director is named Gerald).
La guerra actual en el Medio Oriente nos preocupa mucho (The current/present war in the Middle East worries us).
When you really do mean "real" use verdadero or real or efectivo. Observe these examples. It might even help to memorize them if "actual" is a recurring problem for you. Note that real can also mean royal, as in la familia real (the royal family).
Juana es una amiga verdadera (Jane is a real/true friend). You could also use real or even efectiva instead of verdadera in this sentence.
La historia verdadera fue que Juan nunca robó nada (The real story was that John never stole anything). Note how real means true in the English translation?
The phrases en realidad or a decir [la] verdad correspond to the use of actually, when in English you mean in truth, the truth be told or to tell the truth. Examples:
En realidad, no les gustan las anchoas (Actually, they don't like anchovies).
Ella le traicionó, a decir verdad (She cheated on him, the truth be told).
Finally, when turned into an adverb -- actualmente, or used in a prepositional phrase -- en la actualidad -- you can see how it means nowadays, or at the moment:
Mis padres actualmente viajan por Europa (My parents are currently traveling in Europe).
Ella trabaja en un restaurante en la actualidad (She works in a restaurant right now/nowadays).