Even though I can explain what dimensions higher than the 3rd are, I cannot visualize these objects. I'm speaking of 4 SPATIAL dimensions. First let me explain the difference between a SPATIAL dimension and a VARIABLE dimension. A variable dimension is an independent factor (such as time) that effects the outcome of certain events or ideas. Time is NOT the 4th dimension!! Time is A 4th dimension. It is a VARIABLE 4th dimension.
As for spatial dimensions, back in algebra class we learned that points can be plotted on the x-y plane. The x-y plane is 2-dimensional (hence, x and y dimensions). In multivariable calculus (and basically in your environmental surroundings) you'll learn that there are 3 dimensions of space usually denoted x, y, and z.
There exists a pattern in the properties of all n-dimensional spatial directions: each axis forms a 90° angle with all the other axes. That is, each and every axis of n-dimensional space is perpendicular to each and every other axis of the same n-dimensional space.
For example: The x-axis in the x-y plane is perpendicular (forms a 90° angle) with the y-axis, and vice versa. The x and y axes form 90° angles with the z-axis in 3 dimensions (this works associatively with all other axes). Another way of looking at this is, if you ignore the z-axis, you have an xy plane, if you ignore the y axis, you have the xz plane, and if you ignore the x axis, you have the yz plane.
Now, in 4th-dimensional space, you'd have four axes of space (perpendicular to each other) to visualize. Let's call them w, x, y, and z. It could also be said that the wx plane is perpendicular to the xy plane is perpendicular to the yz plane is perpendicular to the wz plane is perpendicular to the xz plane is perpendicular to the wy plane.
For n-dimensional space, nCr(n, 2) = n!/(2!*(n-2)!) (where ! represents the factorial function) represents the number of planes that n-dimensional space can be seperated into, and they all have the same property: They're all perpendicular to each other!
Being perpendicular is all fine and well for 2d or 3d space, but when it comes to FOUR seperate axes (for 4 dimensions) being perpendicular to each other, the visualization process becomes a mess. Which is exactly the reason I can't think of an easy way to visualize objects in higher dimensions, but I do hear there are books.
Some people have written books to explain the ideas of looking from a lower dimension into a higher one. I hear Flatland: A romance of many dimensions
http://www.math.brown.edu/~banchoff/gc/Flatland/
is a good source for some of these transitions.