Alex, I tend to agree with the advice most other posts offered that 4 months is possibly too early to start a baby on solids.... also the baby's iron stores should last for quite some time...

WHY do you want to start solids now?... is your son not growing well?... do you get the impression he's hungry?... are there problems with breast feeding?... if none of the above is relevant and the baby is doing fine, breast feeding can go on exclusively for several more months... it depends on the individual baby and the breast-milk...

as to what to give once solids are introduced, you could try the meat and vegetables used for making chicken stock [from fresh chickens not roasted carcasses] mashed up with some of the stock liquid, mashed fruits incl. avocados, most things that you eat just slightly mashed up as they can't chew and you don't want them to choke on chunks of food... I even gave my kids home-made nut butter diluted with vegetable bouillon so it was more like mayonnaise in consistency... 
BTW - babies taste buds are not fully developed/functional till about 6-7 months old ! 

best wishes for you and the baby,
Dedy

 Alex Shvartsman wrote on  Sunday, October 05, 2003 4:02 PM
<<I am starting my 4 month old son on solid foods soon. The doctors recommend
iron fortified rice cereal. I want to start with fruits and veggies, but I am concerned about anemia. what ate good sources of iron that can be fed to a 4 month old?
Thanx, Alex>>