Hi,

I am new to Inkspace after trying to work with Gimp. I started with Gimp while using my camera but I decided I want to do something more with art.

Now I jumped into Inkscape to draw verctor images, but I miss something like a rectangle tool (selection area) for a part so I could erase with straight lines (rectangles) for example.

Is this possible in Inkscape? Where can I find it?

For example I use the letter (m) and i want to erase with a straight line through the m from left to right

How can I do this?

Yes, inkscape can do. 

Take your "M", Then create a rectangle, with the rectangle-tool. Place it on top of your "M". Then select your M and the rectangle (hold SHIFT to do so). 
Than use the path menu (PATH > DIFFERENCE) and voila. 

You can use PATH > EXCLUSIVE or PATH > OVERLAPP (at least that would be the translation for the german menu items).

I attached an exampe, you can use to find out how it works. 

You should before understand the difference between a raster application software vs a vector application software.

It worked! Thanks @mondspeer ...

@Gnuserland I'm pretty new to vector. I used Gimp for my photos, but I've decided to learn something more next to my photography hobby.