Hi there,
I am in exactly the same situation as you are, and I spoke to my maternal health nurse who agreed with my thoughts that Tyson should start solids at around 4 1/2 months. I actually started him at 4 months, as he was not putting on weight and my milk supply had tailed off (now I realise that I was feeding him too frequently and he was just snacking).
He has taken to solids amazingly well, he now has the whole tongue thing sorted out (initially they will frustrate you by pushing every spoonful out) and his appetite is nothing short of spectacular. He is now putting on about 250g per week (up from less than half that, some weeks no weight gain) and is sleeping brilliantly.
I started with rice cereal, but am not so keen on that as it seems to constipate him. I have moved towards oatmeal, which I mix with mashed sweet potato, pumpkin, apple, pear, prunes, and his favourites, banana and zucchini (but not all together of course!!!!).
I felt that as a breastfeeding mother who wishes to continue to feed for as long as possible, he needed to be on solids so that I only needed to send him to child care with one bottle of expressed milk (I have been expressing every day and have a stockpile in my freezer!!). My plan is to nurse when I drop him off, he has a bottle with lunch, and then I nurse when I pick him up. He may actually not need so much breast, but I think that's a good starting point.
As I said, he has taken to solids so well, and I am sure that is because Mum helped him start. At the present time, he is on only one solid meal per day, but over the next weeks until I return to work I intend to introduce him to 3 meals, but of course with breastmilk as the main nutrition those meals will simply be hunger-busters.
Hope this helps, and good luck with your return to work. I personally am looking forward to the grown-up company, but am not looking forward to leaving my ds with others to raise. :cry: