We illustrate and discuss the computer-assisted study (approximation and visualization) of two-dimensional (un)stable manifolds of steady states saddle-type limit cycles fr Rows in R(n). Our investigation highlights a number of computational issues arising in this task, along with our solutions "quick-fixes" for some of these problems. Two examples illustrative uf both successes and shortcomings of our current approach are presented. Representative "snapshots" demonstrate the dependence of two-dimensional invariant manifolds on a bifurcation parameter as well as their interactions. Such approximation and visualization studies are a necessary component of the computer-assisted study and understanding of global bifurcations.