The Intel/AMD processor manuals fully describe the operation of each of the integer and floating-point arithmetic instructions, including a detailed description of how these instructions affect the condition code bits and other flags in the EFLAGS and FPU status registers. To write the best possible assembly language code, you need to be intimately familiar with how the arithmetic instructions affect the execution environment, so spending time with the Intel/AMD manuals is a good idea.
The HLA Standard Library provides a large number of floating-point functions for which there are no individual machine instructions. The HLA Standard Library also provides functions like math.sin and math.cos that overcome limitations of the native machine instructions. See the HLA Standard Library reference manual for more details. Also, the HLA Standard Library is available in source code form, so you can look at the implementation of these mathematical functions for more examples of floating-point coding.
Chapter 8 discusses multiprecision integer arithmetic. See that chapter for details on handling integer operands that are greater than 32 bits in size.
The 80x86 SSE instruction set found on later members of the CPU provides support for floating-point arithmetic using the SSE register set. Consult http://webster.cs.ucr.edu/ or the Intel/AMD documentation for details concerning the SSE floating-point instruction set.