How many phosphates are in the 5' end of a DNA strand?
The DNA polymerase can only extend a primer and therefore almost all lifeforms have a primase (which is a type of RNA polymerase) that synthesizes RNA primers at the replication origins that the DNA polymerase can extend. 

As you guessed, the 5' end would indeed have a triphosphate. 


  Organism            Template Sequence        Primer Synthesized
Herpes simplex-1        3′-GPyPy                 pppPuPu
T4                      3′-TTG                   pppAC
T7                      3′-CTG                   pppAC
E. coli                 3′-GTC                   pppAG
S. aureus               3′-ATPy                  pppAPu
S. aureus               3′-ATPy                  pppAPu
A. aeolicus             3′-CCC, CCG, CGC         pppGG, pppGC, pppCG
B. stearothermophilus   3′-ATPy                  pppAPu
Human                   3′-PyNN                  pppPuNN
Calf                    3′-PyNN                  pppPuNN

  Initiation sites used by primase from different sources. Pu = purine, Py = pyrimidine, N = any base ppp = the triphosphate on the 5′-end of the primer. Those bases that are required but do not code for a base in the primer (“cryptic” nucleotides) are underlined and in bold.
  
  Kuchta and Stengel (2010)


In the final stages of replication, these RNA primers are removed by RNAseH and DNA polymerase I in bacteria and the gaps are filled by the latter (Cooper (2000) The Cell). In eukaryotes, the primer is removed by the action of Fen1 and Dna2 exonucleases and the gaps are filled by DNA polymerase &delta; (Burgers 2009).

In PCR, it is quite straightforward: the product will have whatever 5' modifications the primers have (usually none).