In a Ramsey reset test, you test whether all higher order terms coefficients are zero or not. If the null-hypothesis that all such coefficients are zero is rejected, then the model suffers from misspecification.
Depending which software you are using you may get an output that prints test statistic and p-value. If p-value is less than 0.05 for example, then you'd reject. You can try this in R:
library(lmtest)
x <- c(1:30)
y1 <- 1 + x + x^2 + rnorm(30)
y2 <- 1 + x + rnorm(30)
resettest(y1 ~ x , power=2, type="regressor")
resettest(y2 ~ x , power=2, type="regressor")
